OS/2 Shareware BBS: SysTools/SysTools.zip/trydcf14.zip/DCF2.HLP

OS/2 Help File | 1995-04-01 | 162KB | 4,498 lines

ΓòÉΓòÉΓòÉ 1. New in DCF/2 Version 1.4! ΓòÉΓòÉΓòÉ

With this newest version of the DCF/2, we have made significant improvements in
performance and drive reliability.  Some of the changes -- like the new "Clean
& Close" feature -- are transparent to the user.

Other new features will make using the DCF/2 more intuitive and easier to use.
These include:

          Startup Manager (customizes your DCF/2 and system startup)

          New Optimize Utility (includes both menu and command line interfaces)

          Auto-Optimize (recovers free space during run-time)

          Run-time Space Maps (provides graphical description of space usage)

          Snapshot (provides a convenient table listing all of your drives,
          their size, format and space available)

          "Hot Keys" (key combinations allow you to view drive statistics,
          launch DCF/2 help or the DCAT utility.)

          Mount/Dismount Virtual Disks (temporarily mounts or dismounts VDU
          files)

          New Environment Settings (allow you to set your compression rate &
          level -- or "turn off" compression altogether to speed run-time
          performance)

          New Space Management (eliminates the DCF2INFO.CMD!)

          All New Online Documentation (provides all the information you need
          to use the DCF/2)

 The DCF/2 Online Help covers the following topics.  Click on the highlighted
 topic to get help.

       o  Introduction
       o  "The Big Picture"
       o  Installation
       o  OS/2 System Startup
       o  OS/2 File Systems
       o  User Reference
       o  VDU Maintenance
       o  Troubleshooting
       o  Glossary of Terms
       o  Appendix


ΓòÉΓòÉΓòÉ 2. Introduction ΓòÉΓòÉΓòÉ

The DCF/2 is an "on-the-fly" data compression facility which allows you to
increase the effective data storage capacity of your OS/2 computer system.  The
DCF/2 is unlike the traditional "on-the-fly" data compression products
available to DOS users.

Unlike DOS compression products, which require you to pre-allocate the total
size of the compressed drive -- the compressed drives you create using the
DCF/2 grow dynamically.

     For example, when you create a 100MB compressed drive and format it, it
     occupies less than 350K of physical space -- you can create your first
     compressed drive (called a "virtual" disk disk unit" or a "VDU") even if
     you are down to your last few megabytes of physical space!

 Unlike DOS compression products, the DCF/2 does not automatically compress the
 contents of the "host" drive.  Instead, you decide what you want to move to
 compressed storage.  As you move your data onto your "virtual disk unit", you
 recover physical space on its "host" drive.

 Unlike DOS compression products, DCF/2 compressed drives are formatted using
 OS/2's High Performance File System.  With the DCF/2, you can experience the
 speed and efficiency of this powerful file system without reformatting or
 repartitioning your existing physical disk drive.

 Unlike DOS compression products, DCF/2 compressed drives can reside on any
 device supported under OS/2 -- network and removable media (read-write or
 magneto opticals and floppies, etc.) included!

 Unlike DOS compression products, the DCF/2 is a full 32-bit utility --
 designed to grow with your OS/2 desktop.


ΓòÉΓòÉΓòÉ 2.1. The DCF/2 and OS/2 Version Support ΓòÉΓòÉΓòÉ

The DCF/2 requires OS/2 2.x or greater and computer hardware which meets or
exceeds OS/2's minimum system requirements.  According to IBM, the minimum
requirement to run OS/2 is an Intel 386 SX-compatible or higher based personal
computer with 4 MB of random access memory (RAM).  We recommend a minimum
system configuration of an Intel 486 SX-compatible or higher based personal
computer with 8 MB of RAM.  In addition, full HPFS support requires OS/2 2.11
or greater.

If your system is running OS/2 2.0 or 2.1, you will only be able to place
compressed virtual disks on non-HPFS formatted partitions or devices.  The
DCF/2 does not support versions of OS/2 prior to OS/2 2.0.  Rather, we strongly
recommend that you upgrade your operating system to OS/2 2.11 or OS/2 WARP 3.0.

If you are not sure which version of OS/2 is on your system, you can query
OS/2.  Go to an OS/2 window or full screen and type:  SYSLEVEL

DCF/2 Virtual Disk Units are always formatted as HPFS volumes.  If you do not
currently have the High Performance File System installed on your system, the
DCF/2 installation program will either install the correct version for you,
based upon the version of OS/2 running on your system (OS/2 2.1 & 2.11) or
require you to use OS/2's SELECTIVE INSTALL feature to install it (OS/2 Warp).

For more detailed information about the installation of the High Performance
File System as it applies to the version of OS/2 running on your computer
system, please select from the following headings the one that applies to your
computer system:

       o  OS/2 3.0 and HPFS Installed
       o  OS/2 3.0 and HPFS Not Installed
       o  OS/2 2.11 and HPFS Installed
       o  OS/2 2.11 and HPFS Not Installed
       o  OS/2 2.0 or 2.1 and HPFS Installed
       o  OS/2 2.0 or 2.1 and HPFS Not Installed


ΓòÉΓòÉΓòÉ 2.1.1. OS/2 3.0 and HPFS Installed ΓòÉΓòÉΓòÉ

If you are running OS/2 3.0 with the HPFS installed, you're in great shape! The
DCF/2 installation program will leave your existing HPFS.IFS and UHPFS.DLL
files unchanged.


ΓòÉΓòÉΓòÉ 2.1.2. OS/2 3.0 and HPFS Not Installed ΓòÉΓòÉΓòÉ

If you are running OS/2 3.0 without the HPFS installed, the installation
program will report a FATAL ERROR and the program will terminate.

If this happens, you need to use OS/2's SELECTIVE INSTALL feature to install
the High Performance File System on your computer before continuing.  This
isn't difficult, but will require your OS/2 disks.  From the desktop:

       1. Double click on OS/2 System icon
       2. Double click on System Setup icon
       3. Double click on Selective Install icon
       4. Click on OK
       5. Click on the check the box in front of HIGH PERFORMANCE FILE SYSTEM
       6. Click on INSTALL.
       7. Follow the prompts.
       8. Once the HPFS is installed, you are ready to run the DCF/2
          installation program.


ΓòÉΓòÉΓòÉ 2.1.3. OS/2 2.11 and HPFS Installed ΓòÉΓòÉΓòÉ

If you are running OS/2 2.11 and the HPFS is installed, but the version the
version is older than the one shipped on the DCF/2 distribution diskette, the
DCF/2 installation program will make a backup copy of your existing file and
then replace it with the HPFS.IFS dated April 19, 1994.


ΓòÉΓòÉΓòÉ 2.1.4. OS/2 2.11 and HPFS Not Installed ΓòÉΓòÉΓòÉ

If you are running OS/2 2.11 and the HPFS is not currently installed on your
system, the DCF/2 install program will install the OS/2 2.11 UHPFS.DLL and the
HPFS.IFS dated April 19, 1994, to the correct directories and will add the HPFS
statement to your CONFIG.SYS.  (If your existing HPFS file is later than April
19, 1994, it is left unchanged.)


ΓòÉΓòÉΓòÉ 2.1.5. OS/2 2.0 or 2.1 and HPFS Installed ΓòÉΓòÉΓòÉ

If you are running version 2.x of OS/2 but prior to 2.11, have the HPFS
installed and have partitions formatted as HPFS, the HPFS will be left
unchanged.

IN THIS CASE, DO NOT CREATE DCF/2 VIRTUAL DISK UNITS ON YOUR HPFS FORMATTED
PARTITIONS -- USE ONLY FAT-BASED HOSTS.

We strongly recommend that you upgrade your operating system to 2.11 or 3.0.


ΓòÉΓòÉΓòÉ 2.1.6. OS/2 2.0 or 2.1 and HPFS Not Installed ΓòÉΓòÉΓòÉ

If you are running version 2.X of OS/2 but prior to 2.11 and do not have the
High Performance File System installed, the DCF/2 installation program will
install the OS/2 2.1 GA UHPFS.DLL and HPFS.IFS and insert the HPFS statement in
your CONFIG.SYS file.

We strongly recommend that you upgrade your operating system to 2.11 or 3.0.

The remainder of this introduction will present a few of the basic terms that
you will encounter frequently throughout this document.


ΓòÉΓòÉΓòÉ 2.2. Basic Terms ΓòÉΓòÉΓòÉ

Installing the DCF/2 is easy once you have a grasp of the basic terminology.
The most important of these terms describe the differences between the three
different types of storage you can have on a computer -- physical, logical and
virtual.  (Sound scary?  It's not.)

Physical Disk Unit

Your hard disk or hard drive is a Physical Disk Unit (PDU).  You can reach out
and touch it.  You use low level utilities like FORMAT and CHKDSK on it.  It
may have one or more "logical" partitions, which will are identified with
individual drive letters, such as D:, E:, etc.

Logical Disk Unit

A network drive is a Logical Disk Unit (LDU).  You cannot reach out and touch
it.  You cannot perform physical operations on it.  You cannot run low level
utilities like FORMAT and CHKDSK on it.

Each logical disk unit will also have its own drive letter as assigned to it by
the network.

Virtual Disk Unit

A DCF/2 Virtual Disk Unit (VDU) is a hybrid of the two.  It looks like a real,
physical disk unit to OS/2.  It has real geometry (so many heads, so many
sectors per track) and a drive letter.  You can run low level utilities like
FORMAT and CHKDSK on it.  Like a logical disk unit, it does not exist in the
physical sense.

A virtual disk unit has two parts.  The first is an identifying drive letter.
The second is the virtual disk container file.

The virtual disk container file is a is a simple, flat file with no EAs
(extended attributes), which provides storage for your data in compressed
format.  Because it is just a flat file, it can reside on any device supported
by OS/2 -- be that FAT, HPFS, network server or removable media.

Definitions for other commonly used terms are included in the "Glossary of
Terms."  An overview of the DCF/2 is provided in "The Big Picture."


ΓòÉΓòÉΓòÉ 3. The DCF/2 Big Picture ΓòÉΓòÉΓòÉ

The DCF/2 is an on-the-fly data compression facility for all OS/2 file systems.
Transparent to all standard DOS, Windows, and OS/2 applications software, the
DCF/2 works with all existing disk structures -- NO repartitioning of your
existing system is needed.

                   Only the DCF/2 lets you try on-the-fly data
              compression without requiring you to commit yourself
                and your entire computer system to it in advance.

Your virtual disk's host drive can be an existing FAT or HPFS partition, a
network drive -- even removable media like floppies or read/write or magneto
optical drives.  (For users running OS/2 2.0, OS/2 2.1 or or OS/2 for Windows,
only FAT-based host storage is supported.)

The DCF/2 is a system of building blocks designed to grow with your entire
operating environment -- IBM's OS/2 32-bit multitasking makes it all possible!

The following topics are covered in this section:

       o  Product Architecture
       o  How It Works
       o  Compression


ΓòÉΓòÉΓòÉ 3.1. Product Architecture ΓòÉΓòÉΓòÉ

The following diagram of the DCF/2's architecture details these building
blocks:

                             The DCF/2 Architecture

The DCF/2 is designed with each element externalized and modular. This allows
third-party developers to add compression, encryption, and other disk related
capabilities to their system environment (contact the PSC technology lab for
pricing and details of the DCF/2 CDE API kit).

It also allows us to "plug-in" a new module -- for example, a faster, better
compression engine -- or delete an existing one, quickly and easily.  The
remaining modules are unaffected.


ΓòÉΓòÉΓòÉ 3.2. How It Works ΓòÉΓòÉΓòÉ

When the operating system or an application program requests disk accesses, the
DCF/2 Physical Device Driver (PDD) receives the request and repackages it for
processing by the Ancillary Control Process (ACP).  The ACP is a standard,
high-level software layer which shuffles the compressed disk request between
Compression/Decompression Engines (CDE's), Input/Output Engines (IOE's), and
physical disk structures.

The ACP's compressed disk requests are processed and managed by standard OS/2
disk and file services.  This means that the DCF/2 can use all logical media,
such as hard disk drives, LAN network drives, and removable media like
floppies.  This architecture guarantees compatibility with all OS/2 system and
application software updates.

The DCF/2 makes full use of all OS/2 file and memory management features, so
that applications "see" a virtual disk as a "real" disk.

The DCF/2 takes advantage of the OS/2 High Performance File System, allowing
virtual disks to utilize all of the HPFS's advanced features like 254 character
file names, integrated extended attributes, and support for HUGE disks.


ΓòÉΓòÉΓòÉ 3.3. Compression ΓòÉΓòÉΓòÉ

There are two basic kinds of data compression:  (1) Lossless and (2) Lossy.
Lossless data compression requires that whatever goes into the compression
engine comes out in the same form.  Lossy compression allows for statistical
recovery of information -- allowing data dilution.  The DCF/2 supports only
lossless data compression technologies!

Uncompressed sectors are passed through the DCF/2's character-based compression
engine.  The resulting logical disk sectors (LDS) require less physical space
than their uncompressed counterparts.

Each virtual disk unit has an intelligent disk allocation table (DAT) which
describes where compressed logical disk sectors reside within the container
file.

       o  What to Compress
       o  Compressing Compressed Files
       o  What Not to Compress
       o  Compressing OS/2 Itself


ΓòÉΓòÉΓòÉ 3.3.1. What to Compress ΓòÉΓòÉΓòÉ

The DCF/2 includes a utility called the "Disk Compression Analysis Tool" or
"DCAT."  It allows you to look at the data on your system in terms of the
amount of physical disk space that will be returned to you as a result of
moving your data to compressed storage on a virtual disk.

You can use the DCAT to look at your whole physical disk unit or at directories
and subdirectories on your logical drives.  You can sample data in a variety of
ways depending upon your needs.

In general, you will find that user files compress best.  For example, Lotus
AmiPro user files compress at about 5:1.  Windows and DOS program files
compress next best -- usually at 2:1 and better.  Game files compress poorly at
1.5:1.

For detailed information about specific programs and file types, please refer
to the Appendix in your copy of the Disk Compression Facility for OS/2
Introduction.


ΓòÉΓòÉΓòÉ 3.3.2. Compressing Compressed Files ΓòÉΓòÉΓòÉ

Some files won't compress or will compress very little.  These include files
you have archived with utilities like ZIP(tm), PKZIP(tm), ARC(tm), and
LHARC(tm), and files that are shipped already compressed -- for example, game
and sound files.

While they do not compress particularly well, they do still compress a little.
They can be moved to a virtual disk.


ΓòÉΓòÉΓòÉ 3.3.3. What Not to Compress ΓòÉΓòÉΓòÉ

Some files should not be compressed at all.  For example, you would not move
the following to a virtual disk:

       o  Files needed to boot your OS/2 system
       o  Base Device Drivers, e.g., BASEDEV=IBMKBD.SYS, etc.
       o  Files you want access to if you boot an operating system other than
          OS/2

 All files needed to boot your system must be left uncompressed, because they
 are required before your compressed virtual disk units are available.  (For
 more information on compressing OS/2, refer to the following section on
 Compressing OS/2 Itself.)

 New in DCF/2 Version 1.4!.  The DCF2MGR.SYS included as an option with this
 version, starts the DCF/2 control program during OS/2's system initialization
 rather than after it.  This makes your virtual disks available in time for
 OS/2 to load an application's device driver from a virtual disk.

 The early startup is an option, not the default.  To use it, you need to
 remove the REM >> from in front of the DEVICE=DCF2MGR.SYS statement in your
 CONFIG.SYS.

 When the DCF2MGR.SYS is used to start the DCF/2, applications that load device
 drivers from your CONFIG.SYS file can be moved or installed to a virtual disk.
 Just make sure that their DEVICE= statement in your CONFIG.SYS file is AFTER
 the DCF/2 DEVICE= statements.

 Devices created by base device drivers (BASEDEV= statements in your
 CONFIG.SYS)  should not be moved to compressed storage, because OS/2 loads
 these before the virtual disks are available.

 If you use Dual Boot or Boot Manager to boot an operating system other than
 OS/2, you should leave uncompressed files you need or want access to from an
 operating system other than OS/2.  Data stored on your DCF/2 virtual disk
 units is not accessible when you boot native DOS.


ΓòÉΓòÉΓòÉ 3.3.4. Compressing OS/2 Itself ΓòÉΓòÉΓòÉ

The operating system (OS/2) is like a puzzle which rebuilds itself each time
you "reboot" your system.  It does so in phases.  The first is system
initialization.  The second is system startup.

During system initialization, base device drivers, device drivers, and basic
system-wide information load.  The DCF/2 device drivers (DCF2MGR.SYS,
DCF2PDD.SYS and DCF2CDE.SYS) load at this time.

The DCF2MGR.SYS launches the DCF/2 control program (DCF2.EXE) which spawns the
DCF/2 ancillary control process (DCF2ACP.EXE) and initializes your virtual
disks.

During system startup the operating system loads high-level file services, user
interface and management programs (Presentation Manager), and initializes
user-specific actions (STARTUP.CMD and STARTUP FOLDER).

New in DCF/2 Version 1.4 is the early startup during OS/2 system
initialization. While it allows you to move most of OS/2 to virtual storage --
everything but OS2KRNL, OS2LDR and the DLLs -- we do NOT recommend moving OS/2
to a virtual disk.

We recommend that you allocate to OS/2 the space it requires and compress your
application software, utilities, user files and things like icons, clipart and
communications threads, etc.

Note:  That said, you can move some parts of OS/2 to a VDU and run them quite
       successfully.  For example, you can move WINOS2 to a VDU to free up
       about 8MB of space on your OS/2 boot drive.  (When you do so, you must
       modify the OS/2 PATH and DPath statements to properly reference the new
       WINOS2 subdirectory.  Also modify the AUTOEXEC.BAT file to point to the
       new WIN\OS2 directory.)

If you installed them, you can also gain additional space on your OS/2 boot
drive by moving EPM (the Enhanced Editor) and OS/2 reference files (.INF) to a
VDU.


ΓòÉΓòÉΓòÉ 4. Installation ΓòÉΓòÉΓòÉ

The installation process includes creating VDUs, copying the DCF/2 program
files to a target directory, updating your CONFIG.SYS file and restarting your
system.

The DCF/2 Version 1.4 installation program can be used to both install the
DCF/2 for the first time and/or to update existing DCF/2 program files.  If you
are updating existing DCF/2 program files and want to add additional VDUs, you
may do so.  The install program will scan for existing VDUs and report that
number in the box next to "Total VDUs".  To create additional VDUs, increase
this number.

To run the DCF/2 Installation program, change to the source drive (or temporary
directory) and type:  INSTALL.

Attention Network Clients  If you use a LAN and the LAN drives letters you use
                           are adjacent to your first physical drive letter,
                           they will have to be moved to after the VDU drive
                           letters.  If you have network drives defined, please
                           logoff of the network prior to running the DCF/2
                           install program.

 Related topic:

                    Installing from a Network or OnLine Service

 The following topics are covered in the remainder of this sections:

       o  Choosing the Target Drive
       o  Selecting the Number of VDUs
       o  Creating VDUs
       o  Updating the Configuration
       o  DCF/2 Icons & README
       o  Restarting Your System
       o  Formatting VDUs
       o  AutoChecking VDUs
       o  Moving Data to VDUs
       o  Shut Down
       o  Installing from a Network Server
       o  Updating Workstation from a Server
       o  Registration


ΓòÉΓòÉΓòÉ 4.1. Choosing the Target Drive ΓòÉΓòÉΓòÉ

The "DCF/2 Installation" screen asks you to select the "Target Drive" for the
DCF/2 program files.  The target drive is the uncompressed physical drive from
which OS/2 will run the DCF/2 programs.


ΓòÉΓòÉΓòÉ 4.2. Selecting the Number of VDUs ΓòÉΓòÉΓòÉ

On the "DCF/2 Installation" screen you will enter the "Total VDUs" to be
created by the install program.  (If you change your mind later, you can add or
remove VDUs using the DCF/2 control program.  So, don't worry about creating
too few or too many now.)

No two systems are alike.  Some users have a single C: drive. Other users have
two physical drives divided into multiple logical partitions. Still others have
network drives, CD-ROMs and Read/Write or Magneto Optical devices installed.

Included below are some guidelines to consider as you determine the number of
VDUs to create.

       o  Based Upon Data by Frequency Written/Read
       o  Based Upon Data by Type
       o  Based Upon the Number of Partitions or Devices
       o  Recommendations


ΓòÉΓòÉΓòÉ 4.2.1. Based upon Data By Frequency Written/Read ΓòÉΓòÉΓòÉ

Some of the data on your computer is written and read infrequently.  Some is
written only once but read often -- for example, programs are written only when
you install them but are read every time you use them.  Some is read and
written often -- your user files are a good example.

Consider dividing your data based upon the frequency with which the data to be
stored in virtual disks is read and/or written.  Then create one  or more
virtual disks for data which is seldom written/seldom read, one for data
written seldom/read often and one for data written and read often.

The data on a system usually falls into one of three categories and occupies
more or less a fixed percentage of the physical space.  (Most but not all of
OS/2 falls into the "write seldom / read often" category -- the SWAPPER.DAT and
.INI files are "read often / write often.")

                      Data Categorized by Frequency of Use

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ΓöéCategory                 ΓöéAs % of Physical    ΓöéExamples                 Γöé
Γöé                         ΓöéSpace               Γöé                         Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
ΓöéWrite seldom/Read seldom Γöé60 %                ΓöéIcons, .pic files,       Γöé
Γöé                         Γöé                    Γöécommunications threads,  Γöé
Γöé                         Γöé                    Γöétutorials, online        Γöé
Γöé                         Γöé                    Γöéarchives, database       Γöé
Γöé                         Γöé                    Γöébackups, etc.            Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
ΓöéWrite seldom/Read often  Γöé25%                 ΓöéApplications and most of Γöé
Γöé                         Γöé                    ΓöéOS/2                     Γöé
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ΓöéWrite often/Read often   Γöé15%                 ΓöéLive data including the  Γöé
Γöé                         Γöé                    ΓöéOS/2 swapfile and .INI   Γöé
Γöé                         Γöé                    Γöéfiles                    Γöé
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ΓòÉΓòÉΓòÉ 4.2.2. Based Upon Data by Type ΓòÉΓòÉΓòÉ

Another approach is to create VDUs based upon the kind of data to be stored in
them.

Using this approach, you would create one virtual disk for programs, one for
utilities, one for user files, and so on.  If you have lots of programs and a
large disk, you might create more than one VDU for programs.

You might also want to create "online" archives to store data and files you
refer to only infrequently but are not yet ready to remove from your system
altogether.


ΓòÉΓòÉΓòÉ 4.2.3. Based Upon the Number of Partitions or Devices ΓòÉΓòÉΓòÉ

Still another method for determining the number of VDUs to create is to create
one or more for each of the partitions or devices on which you have data that
you would like to move to compressed storage.

You may decide to create a VDU for each logical partition or device, or to
create several small VDUs on a single partition.  You may elect to skip a
partition or device altogether.

Note:  If you are using a laptop with a docking station, you may want to create
       an additional "dummy" VDU for each of the devices present when docked
       but missing when running portable.  (Refer to the section on laptops in
       "Tips & Techniques.")


ΓòÉΓòÉΓòÉ 4.2.4. Recommendations ΓòÉΓòÉΓòÉ

For a number of reasons, we recommend that you create multiple VDUs rather than
a single large one.  Creating multiple VDUs gives you:

       1. Greater control over what you compress where
       2. Greater flexibility in creating and maintaining backups of your data
       3. Greater control over the time required to CHKDSK your disks
       4. Greater control over the time required OPTIMIZE your disks

 The amount of time required by the CHKDSK and OPTIMIZE programs can go up
 dramatically as the size of the virtual disk increases!

 If you have a 1 GB hard drive, you don't want to create a single 2 GB virtual
 disk. Instead, create two 512 MB and four 256 MB VDUs.  Doing so will save you
 time and allow you to work much more efficiently.

 While the DCF/2 allows you to create as many or as few VDUs as suit your
 needs, if the number is greater than 5, you may need to start only the first 5
 using the SET command environment variables in your CONFIG.SYS file.

 Related topic:

          Startup with more than 5 Virtual Disks


ΓòÉΓòÉΓòÉ 4.3. Creating VDUs ΓòÉΓòÉΓòÉ

The first VDU you create will take the first drive letter available on your
system; the second will take next available drive letter, and so on up to the
total number  of VDUs you requested be created.  p.For each VDU, you select the
drive letter for the "Host  Physical Unit for VDU" and the "Total Size in MB."

Note:  The DCF/2 will allocate its VDU drive letters contiguously from the
       first available physical drive letter on your computer system at the
       time the DCF/2 physical device driver loads.  This means that, for
       example, laptop users with docking stations may need to use one
       CONFIG.SYS when docked and a second CONFIG.SYS when running portable.
       (For WARP users, the appropriate CONFIG.SYS can be chosen at start up
       time using the Recovery Choices Screen -- for details see your OS/2 WARP
       User's Manual.)

Laptop users can also use a single CONFIG.SYS and create an additional "dummy"
VDU to serve as a placeholder for each of the devices that are not there when
running in portable mode.  Refer to Using the DCF/2 on Laptops .

       o  Choosing Where to Put VDUs
       o  Selecting the Host Physical Unit
       o  Selecting VDU Size
       o  Further Selections


ΓòÉΓòÉΓòÉ 4.3.1. Choosing Where to Put VDUs ΓòÉΓòÉΓòÉ

This version of the DCF/2 allows you to create as many virtual disk units as
you have drive letters available.  You can "put" your VDU's on any of your
existing disk units, on network drives, floppies, tape, Read-Write Opticals --
any writeable device supported by OS/2 so long as you are running OS/2 2.11 or
greater.


ΓòÉΓòÉΓòÉ 4.3.2. Selecting the Host Physical Unit ΓòÉΓòÉΓòÉ

The  "Host Physical Unit" is the uncompressed location where the Virtual Disk
Unit resides.  This can be any of your existing FAT or HPFS formatted
partitions or devices or a network drive.  The data you want to compress on the
host drive is the data you will move to the VDU or VDUs that reside on it.

Hints  If your system has a physical C: from which you boot OS/2, and logical
       D: and E:, you should select D: and E: as hosts.

If the Host Physical Unit contains the SWAPPER.DAT file, we recommend that you
preallocate space for the swap file by adjusting the settings in your
CONFIG.SYS.

Because SWAPPER.DAT is entirely under the control of OS/2, it is better to have
it on a partition that is not a host drive so that it does not further
aggrevate an "out-of-space" condition in the event that the amount of physical
space available on the virtual disk's host drive fall below the acceptable
limits.


ΓòÉΓòÉΓòÉ 4.3.3. Selecting VDU Size ΓòÉΓòÉΓòÉ

The VDU's default size is 128 MegaBytes.  This is NOT based upon an in-depth
analysis of the size of the host physical unit you have selected for the VDU.
It is only provided to prevent you from creating a VDU of no size at all.

The "Total Size" is the total capacity of the drive as far as OS/2 is
concerned.  When you run CHKDSK on the drive, this is the size it reports. (If
you were to look at the VDU container file itself on its host drive, the file
will be about half of this size when it is full of data.)

You want the "Total Size" to be greater than -- but close to -- the amount of
storage you want available.  For example, if you have 100 MB of data you want
to compress, you would enter a total size of 100 MegaBytes.

Hint  Remember, an empty 100 MB VDU will initially only require about 350
      Kbytes of space on its "host" drive; when full (i.e., it contains 100 MB
      of data), it will require approximately 50 MB on its "host" drive.

 You can estimate the amount of "virtual space" you can expect to get based
 upon how well the type of data you plan to move to the VDU typically
 compresses. A VDU containing a fairly even distribution of user, program and
 miscellaneous files (e.g., icons, threads, clipart, etc.) will typically
 compress at 2:1.

 You can calculate the estimated total virtual space you'll have available as
 follows:

       1. Start with the total size of your physical drive
       2. Subtract the space required by OS/2, (including the SWAPPER.DAT file)
       3. Subtract the amount of physical space you would like to reserve for
          uncompressed storage
       4. Multiply the result by the typical compression ratio for the type of
          data you plan to compress

 How you allocate the estimated total virtual space is up to you.  You can
 create a single VDU, or, you can create several smaller VDUs.

 Hints  While there is always the temptation to take that 1 GB disk you have
        and create a single, 2 GB virtual disk, DON'T.  The time required to
        purge an empty 2 GB virtual disk of deleted space is time you could
        spend far more effectively!

 If you are uncertain about the typical compression ratios of your data, set up
 just one VDU to implement the DCF/2 and then run DCAT for directories which
 are candidates for compression. This will tell you what will be achieved in
 practice.


ΓòÉΓòÉΓòÉ 4.3.4. Further Selections ΓòÉΓòÉΓòÉ

Once you have indicated your choices, you can choose to "Create or Update VDU,"
get "Help," or "Exit/Cancel."  The latter allows you to change your mind or
correct an unwanted choice.

Following the successful creation of your first VDU, the process repeats itself
automatically for each subsequent VDU up to the total number of VDUs you
requested.

If you are upgrading over a previous version of the DCF/2 and have asked for
additional VDU's to be created, this process wil repeat for just those
additional VDU's.


ΓòÉΓòÉΓòÉ 4.4. Updating the Configuration File ΓòÉΓòÉΓòÉ

Once your VDUs have been created, the DCF/2 program files are copied to the
"Target Drive" and the install program adds the DEVICE, SET and CALL statements
to your configuration file.

Automatic Update

The install program creates the CONFIG.DCF file. This file will replace your
existing CONFIG.SYS.  First, however, your existing CONFIG.SYS is saved as
CONFIG.!D!.

The install program includes an edit option to allow you to edit the load order
of devices in your CONFIG.SYS before completing the installation process and
restarting your system.  In most cases, you will not need to do so.

Whenever the DCF/2 makes a change to your CONFIG.SYS file, that change will
always be delimited by lines and REM statements which explain what was changed
and the date and time stamp of the change.


ΓòÉΓòÉΓòÉ 4.4.1. Example of Changes to the CONFIG.SYS File ΓòÉΓòÉΓòÉ

The order of the statements in the CONFIG.SYS file is adjusted to put the
HPFS.IFS statement at the top, followed by the DISKCACHE statement if there are
FAT-formatted drives.  This is followed by the original CONFIG.SYS statements,
(with the earlier HPFS and DISKCACHE statements REM'd out with a time stamp),
followed by the DCF/2 virtual disk definitions, followed by the DCF/2 CALL
statement:

where x: is the uncompressed drive to which you installed the DCF/2 programs.

          CALL=x:\DCF2\DCF2.EXE /A:STARTUP

 The HPFS and (optionally) DISKCACHE statement(s) may be modified to optimize
 the cache allocation and/or to add AUTOCHECK switches.

 The DCF/2 requires a minimum HPFS cache of 1024.  In the following example,
 the /CACHE parameter determines the number of KiloBytes of memory allocated to
 HPFS cache blocks.  The /AUTOCHECK tells the HPFS to CHKDSK the HPFS disks F:,
 E: and G: if "dirty":

          IFS=C:\OS2\HPFS.IFS /CRECL:64 /CACHE:1536 /AUTOCHECK:FEG

 "Dirty" disks result from improperly shutting down OS/2.  This can be the
 result of voluntary action on the user's part -- turning off the computer
 without running shut down. Or, it can result from an involuntary action -- a
 system TRAP or system hang, or a power failure.

 The DISKCACHE statement is required only if there are FAT drives on the
 system.  If there are no FAT formatted drives, this statement is REM'd out
 thereby freeing up the memory it would have otherwise committed.

 In the following DISKCACHE statement, the first number is the number of
 KiloBytes allocated to FAT caching.  The LW parameter enables FAT
 lazy-writing.  The number following that is the threshold.  The AC: specifies
 which FAT drives to CHKDSK during system startup if 'dirty'.

          DISKCACHE=1024,LW,32,AC:C

 The following "REMed" (commented out) commands can improve your system's
 caching performance, depending upon how the system is used.  To enable them,
 delete the "REM >>" preceding each statement, save the file and restart your
 system.

          REM >> RUN=x:\OS2\CACHE.EXE /MAXAGE:40000
          REM >> RUN=x:\OS2\CACHE.EXE /DISKIDLE:30000
          REM >> RUN=x:\OS2\CACHE.EXE /BUFFERIDLE:20000

 Note:  Due to the multithreaded nature of the OS/2 system startup, you may
        need to place the above RUN commands in the STARTUP.CMD folder instead
        of in the CONFIG.SYS if any problems show.

 The contents of the original CONFIG.SYS file follow these statements and these
 are followed by the DCF/2 DEVICE, SET and CALL statements at the end of the
 CONFIG.SYS. The DCF/2 statements are commented and surrounded with delimiting
 lines.

 The DCF/2 device drivers are order dependent and each must appear on a
 separate line.  The DCF2PDD.SYS comes first, then the DCF2CDE.SYS and
 DCF2MGR.SYS.

          DEVICE=C:\DCF2\DCF2PDD.SYS /u:3
          DEVICE=C:\DCF2\DCF2CDE.SYS
          REM >> DEVICE=C:\DCF2\DCF2MGR.SYS C:\DCF2\DCF2.EXE /a:startup

 The /u: parameter determines the number of VDU devices to create.  The
 C:\dcf2\dcF2.EXE /a:startup command executes the DCF/2 control program during
 system initialization so that programs loading device drivers can no longer
 have to maintain a separate physical directory for their device drivers.

 This version of the DCF/2 includes an optional early startup feature, which
 starts the DCF/2 control program from the DCF2MGR.SYS device driver.  The
 early startup feature works on some systems, but not on others.  Therefore it
 is an option rather than the default.  To use the early startup, remove the
 "REM >>" from in front of the REM >> DEVICE=C:\DCF2\DCF2MGR.SYS
 C:\DCF2\DCF2.EXE /a:startup statement, add REM >> to the CALL=C:\DCF2\DCF2.exe
 /A:STARTUP statement, and reboot.

 The DCF_VDU_x environment variable points to the DCF/2 VDU x: drive's
 container file which by default has an extension .VDU.

          SET DCF2_VDU_E=C:\DCF2\DCF2_E.VDU
          SET DCF2_VDU_F=C:\DCF2\DCF2_F.VDU
          SET DCF2_VDU_G=C:\DCF2\DCF2_G.VDU

 The following DCF/2 diagnostic statements are to aid in diagnosing virtual
 drive characteristics and problems:

          REM >> SET DCF2_ACP_LOGNG=3
          REM >> SET DCF2_ACP_DEBUG=3

 To enable logging and debugging, delete the REM >> at the beginning of these
 lines. PSC Technical Support may request you to do this if you are
 experiencing problems.

 The following statement executes the DCF/2 control program once system
 initialization is complete.

          CALL=C:\DCF2\DCF2.exe /A:STARTUP

 Network Users  The "CALL=" statement starts the DCF/2 control program.  If you
                have put DCF/2 virtual disk units on network disks or other
                media which is not available at boot time, move this statement
                to the STARTUP.CMD or to the command procedure that starts your
                network.

 The REM'd statements and delimiting lines may be deleted if you prefer. Do,
 however, exercise extreme caution so as not to delete more than the comments!


ΓòÉΓòÉΓòÉ 4.5. DCF2 Icons and README.14 ΓòÉΓòÉΓòÉ

DCAT and Online Help Icons

During the final part of the installation, the program will place the DCAT and
DCF/2 Online Help icons on your desktop and display the DCF/2 README file.  It
will then ask if you would like to restart your system at this time.

README.14

The README.14 file shipped on the DCF/2 disk contains the latest release notes
for the software.  You can elect to have both the README.1st and README.14
copied to the DCF/2 program directory when you run the DCF/2 install program.

Regardless, you will have an opportunity to view the file automatically just
prior to exiting the DCF/2 install program and restarting your system.


ΓòÉΓòÉΓòÉ 4.6. Restarting Your System ΓòÉΓòÉΓòÉ

The DCF/2 device statements added to your CONFIG.SYS will not take effect until
such time as your system is restarted.

Before exiting the DCF/2 install program, the program will ask you if you would
like to have your system restarted automatically at this time.  If you answer,
"yes," the install program will run shutdown. Alternatively you can choose to
exit the program and do the reboot later.

Once you have successfully created your VDUs and your system has been rebooted,
each of your VDUs will automatically be formatted using the HPFS format.  On a
standard OS/2 system, this will happen prior to the time OS/2 loads the
Workplace Shell (PM).


ΓòÉΓòÉΓòÉ 4.7. Formatting VDUs ΓòÉΓòÉΓòÉ

The DCF/2 uses the OS/2 FORMAT command to format each VDU as an HPFS volume
automatically.

The formatting process can take from a few seconds to a couple of minutes,
depending upon the size of the drive being formatted and the speed of your
computer.

The format command will prompt you to enter a volume label or press enter.  At
this point, the volume information is written to the VDU's boot record.

Note:  The FORMAT uses an undocumented OS/2 2.1 feature for fast format.  If,
       for some reason, it does not work on your system, answer "no" at the
       fast format prompt. FORMAT will then run on the VDU without the fast
       format switch.


ΓòÉΓòÉΓòÉ 4.8. AutoChecking VDUs ΓòÉΓòÉΓòÉ

The DCF/2 uses OS/2's CHKDSK /F to check the newly formatted drive.  Be sure to
"press any key to continue" when prompted to do so!  This process repeats for
each of the VDUs you created during the installation program.


ΓòÉΓòÉΓòÉ 4.9. Ready for Data ΓòÉΓòÉΓòÉ

At this point, your VDUs are formatted, empty and available.  You may now begin
to move data and user files onto them -- using OS/2's drag and drop feature,
XCOPY and DELETE commands or the tools you normally use to move directories and
files on your system.

New in DCF/2 Version 1.4, you can use a "hot key" to open the OS/2 Drives
object -- place the mouse pointer on the title bar of any virtual disk unit's
LED and click the right mouse button.  Using the Drives object you can copy or
move directories, subdirectories or individual files from physical to virtual
storage.

Related topic:

          Moving Files from Physical to Virtual Space


ΓòÉΓòÉΓòÉ 4.10. Shut Down ΓòÉΓòÉΓòÉ

As of Version 1.2, the DCF/2 shut down was completely integrated with OS/2's
standard "right mouse button" shut down.  Whenever possible, run shut down
before turning off your computer.


ΓòÉΓòÉΓòÉ 4.11. Installing from a Network Server ΓòÉΓòÉΓòÉ

You can install the DCF/2 to a central location on a server. First, make a
directory on the server, e.g., DCF2DIST; then copy the DCF/2 program files to
that directory.

          COPY A:*.* P:\DCF2DIST\*.*

 In the above example, the DCF/2 program disk is in your A: drive and you are
 copying the files to a directory called DCF2DIST on server drive P:

 On each workstation, create a temporary directory; then logon to the
 appropriate network drive and change to the DCF2DIST directory.  Copy the
 files from the DCF/2 program directory on the server to the temporary
 directory on the workstation.  (In, the following example, the temporary drive
 "TMP" is on drive "x".)

          COPY  P:\DCF2DIST\*.* x:\TMP

 Caution  Do not use "DCF2" as the temporary directory name.  If you name the
          temporary directory "DCF2," the installation will fail.

 Before installing the DCF/2, the workstation must logoff of the network. If
 this is not done, the first VDU will take an incorrect drive letter.

 After logging off of the network, the client workstation installs the DCF/2
 from the temporary directory, by changing to the temporary directory and
 running the DCF/2 install program.

       1. Change to the target drive:  x:
       2. Change to the temporary directory:  CD\TMP
       3. Run the install program; type:  INSTALL

 Note:  Installing the DCF/2 from files you have downloaded from an online
        service is similar to installing the DCF/2 from a network server.
        First download the files. Typically they will be in the form of a
        compressed .ZIP or self-extracting .EXE file. Next create a temporary
        directory -- once again, NOT DCF2.  Then unzip or extract the files to
        the temporary directory.  Run the install program as described above.


ΓòÉΓòÉΓòÉ 4.12. Updating Workstation from a Server ΓòÉΓòÉΓòÉ

When the install program is used to update an existing DCF/2 program area on a
client workstation, only the DCF/2 program files are changed unless you request
additional VDUs.  This process can be done directly from the central server and
does not require that the client workstation logoff the network.

If, however, you need to use the install program to create additional VDUs, you
MUST need to logoff the network before creating the VDUs.


ΓòÉΓòÉΓòÉ 4.13. Registration ΓòÉΓòÉΓòÉ

Your DCF/2 package includes a registration card.  Please take the time to fill
out your registration card and return it to us so that we can notify you when
updates to the DCF/2 are available.

You will need to locate your serial or license number. The easiest way to do
this is to look in your DCF2 program directory or on the DCF/2 distribution
diskette for the file LICENSE.DCF.

If you are interested in testing future releases of the DCF/2, please check the
"Beta" test program box.  All registered users who would like to beta test are
eligible to do so.  Access to CompuServe or IBMLink is a requirement.


ΓòÉΓòÉΓòÉ 5. OS/2 System Startup ΓòÉΓòÉΓòÉ

At OS/2 system startup -- on a standard system, running the Presentation
Manager -- the DCF/2 startup process will complete before the Presentation
Manager comes up.

The DCF/2 startup process involves scanning all of the VDUs and formatting
and/or running CHKDSK on any VDUs that are either unformatted or were left
"dirty" by an improper shut down.

During this startup process, you can set the DCF/2 to display a STARTUP menu.
From the menu, you can interrupt the DCF/2 startup processes, launch an OS/2
command processor or abort the loading of the DCF/2 device drivers.

Related topics.

          Startup Manager
          Startup with more than 5 Virtual Disks

 The remainder of this section covers startup on your system of the:

       o  DCF/2 Device Drivers
       o  DCF/2 Control Program
       o  DCF/2 Ancillary Control Process


ΓòÉΓòÉΓòÉ 5.1. DCF/2 Device Drivers ΓòÉΓòÉΓòÉ

The DCF/2 is implemented based upon a physical device driver which creates one
or more block devices (virtual disks) which load from your OS/2 CONFIG.SYS
file.  It is not an "installable file system" (IFS).

The DCF/2 install program placed three device drivers in your CONFIG.SYS file.
OS/2 loads these at system startup.  The device drivers are load-order
dependent. The DCF2PDD.SYS must load first.

The DCF2PDD

The DCF/2 Physical Device driver defines a block device in your CONFIG.SYS that
"creates" your compressed drive or drives.  The DEVICE=DCF2PDD.SYS statement is
followed by "/u:x", where "x" determines how many template block devices (VDUs)
are created.  Each template block device is allocated a drive letter.  Drive
letters begin with the first available drive letter for your system.

The DCF2CDE

The DCF/2 Compression Decompression Engine (DCF2CDE.SYS) is a character-based
device driver.  As requested data passes through it, it compresses or
decompresses that data depending upon whether it is being written to or read
from disk.

The DCF2MGR

The DCF/2 Manager device driver allows this version of the DCF/2 to load during
OS/2's system initialization.  This makes your virtual disks available to OS/2
early enough so that an application's device driver can load from the virtual
disk.

While it works beautifully on some systems, on others it causes a nasty trap.
Therefore, it is included as an option rather than as the default.

Note:  Device statements for devices loading from virtual disks must appear in
       your CONFIG.SYS file AFTER the DCF/2 statements.


ΓòÉΓòÉΓòÉ 5.2. DCF/2 Control Program ΓòÉΓòÉΓòÉ

OS/2 uses the DCF/2 Control Program each time your system starts up.  You can
use the program's command line interface to do the following:

       o  Start and stop the DCF/2 control processes
       o  Create virtual disk container files
       o  Temporarily mount or dismount a virtual disk
       o  View VDU drive statistics
       o  Adjust the Monitor LEDs for a monochrome display

 Refer to the "User Reference" for information on using the DCF/2 Control
 Program


ΓòÉΓòÉΓòÉ 5.3. DCF/2 Ancillary Control Process ΓòÉΓòÉΓòÉ

The DCF/2 Ancillary Control Process (DCF2ACP) is the software controller for
the virtual disk units.  It provides the link between drive x: and its VDU
container file.

There are times when you need to stop the control processes -- for example,
when you do an "image" backup of the virtual disk, or if you use OS/2's dual
boot feature.  You stop and start the control processes using the DCF/2 Control
Program.  From an OS/2 command prompt, use the following command:

 Stop processes:
    DCF2 /A:SHUTDOWN or, DCF2 /-

 Start processes:
    DCF2 /A:STARTUP or, DCF2 /+

   Note:  When the DCF2 Control Processes are stopped, your VDUs and the
          programs and data on them are not available.  If you think in terms
          of your physical disk controller, this makes sense  -- were you pull
          your physical disk controller out of your computer, the programs and
          files on your physical disk would not be available!

 Refer to the "User Reference" for information on additonal features of the
 DCF/2 Ancillary Control Process.


ΓòÉΓòÉΓòÉ 6. OS/2 File Systems ΓòÉΓòÉΓòÉ

A file system is the part of the operating system that provides access to the
programs and files.  It determines how data is stored on a disk.

OS/2 includes two file systems:  the file allocation table (FAT) and high
performance file system (HPFS).  The key difference between the two file
systems is the way in which they manage your data.

The following sections provide a brief overview and comparison of the two file
systems.  For additional information, please refer to OS/2's Online Help.

       o  The FAT File System
       o  The HPFS File System
       o  HPFS vs. FAT Summary
       o  Floppies
       o  OS/2 File Systems and the DCF/2


ΓòÉΓòÉΓòÉ 6.1. The FAT File System ΓòÉΓòÉΓòÉ

As its name implies, the FAT (file allocation table) file system is based upon
a table of entries which contain the allocation information for each file on
the disk.  Entries in the table point to allocation units called clusters. The
table itself is limited in size to 64K entries -- a limit that has its origins
in a time when a hard disk was "optional equipment" and the biggest disk
imaginable was all of 32 MB!

As the size of disk drives has grown beyond 32 MB, the cluster (or minimum
allocation unit) size has had to increase in order to fit the table's 64K
entries.  Gone is the 512 Byte cluster.  Today, a cluster size of 4 (or even 8)
Kbytes is typical.

As the size of your hard disk increases beyond 256 MB, the minimum size of the
cluster you use must increase, too (to 8 or even 16 Kbytes).  The table below
shows both the cluster size and the maximum size disk it will allow:

                                FAT Cluster Sizes

                                    ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
                                    ΓöéCluster Size   ΓöéDisk Size      Γöé
                                    Γöé               ΓöéCannot Exceed  Γöé
                                    Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
                                    Γöé512 Bytes      Γöé32 MB          Γöé
                                    Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
                                    Γöé1 Kbytes       Γöé64 MB          Γöé
                                    Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
                                    Γöé4 Kbytes       Γöé256 MB         Γöé
                                    Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
                                    Γöé8 Kbytes       Γöé512 MB         Γöé
                                    Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
                                    Γöé16 Kbytes      Γöé1 GB           Γöé
                                    ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ

 The file allocation table for a disk is placed in the root directory at either
 the beginning or end of the partition.  When you search for a file on a
 FAT-formatted disk, the entries in the table are searched sequentially,
 beginning with the first entry in the table.

 The FAT file system supports only the "eight-dot-three" convention for file
 names.  That is, file names can use up to eight alphanumeric characters
 followed by a period and an extension of three alphanumeric characters.  For
 example:

                                    MYFILE.DOC
                                  TESTFILE.WK1.

 The FAT file system cannot recognise drives formatted using the High
 Performance File System.


ΓòÉΓòÉΓòÉ 6.2. The HPFS File System ΓòÉΓòÉΓòÉ

The high performance file system (HPFS) was designed for PC's capable of:
multitasking, running in protected mode, using virtual memory and possessing
far bigger disks than the disks the file allocation system was designed to
support.

The High Performance File System (HPFS) stores data at sector granularity --
512 bytes per sector.  The HPFS allocates sectors contiguously and stores
information about each file in the file's nearby "Fnodes".  Because the HPFS
allocates contiguous space for files, HPFS-formatted disks are far less prone
to fragmentation than are FAT-formatted drives.

The root directory on an HPFS disk is at the "seek center" of the partition
rather than at the beginning or end.  Directory and file searches on an HPFS
disk are done using a version of a binary tree called the "B-Tree."  The B-Tree
search is quick and efficient.

The HPFS supports file names of up to 254 characters in length -- in addition
to conventional 11 character file names.  Support for long file names provides
the user with the ability to make file and directory names more descriptive of
their contents.

The HPFS can recognise disks formatted with the FAT or HPFS file system.


ΓòÉΓòÉΓòÉ 6.3. HPFS vs. FAT Summary ΓòÉΓòÉΓòÉ

The FAT works efficiently on the disks for which it was originally designed --
floppies and disk drives of up to 32 MB in size.  But as the size of the disk
drive grows, the FAT tends to become inefficient.  When the FAT is too large to
be kept in resident memory, system performance slows down.  In addition, files
stored on a FAT-formatted disk become fragmented.

Statistically over a FAT formatted drive, one half of the cluster size is lost
(or slack) space.  Actually, it can be worse than that -- especially if you
have a lot of small files, like icons.  Consider the following example:

     An icon is typically slightly less than 1 Kbytes in size, but a
     FAT-formatted partition, with a minimum cluster size of 4Kbytes, will
     require 4 Kbytes to store this 1 Kbyte file.  If you store 4,000 1 Kbyte
     icon files on a FAT partition, you will use 16 MB of space --12 MB of the
     16 MB are in lost space!

     To store the same 1 Kbyte icon file on an HPFS-formatted drive requires
     only 1024 bytes (or two 512 Byte sectors).  To store the same 4,000 1
     Kbyte big icon files that required 16 MB on a FAT-formatted partition,
     requires only 4 MB on an HPFS-formatted volume!  You recover 12 MB of
     physical space simply by storing the files on an HPFS- rather than a
     FAT-formatted volume.

 The HPFS also offers several other benefits.  Among these are its highly
 efficient B-Tree search mechanism, the ability to use up to 254 characters for
 file names, and optional cache tuning parameters which can improve system
 performance by 25 to 30%.


ΓòÉΓòÉΓòÉ 6.4. Floppies ΓòÉΓòÉΓòÉ

A floppy drive is DASD device.  Floppy disks are always formatted using the
File Allocation Table.

Using the DCF/2, you can put HPFS-formatted VDU's on FAT-based floppies.


ΓòÉΓòÉΓòÉ 6.5. OS/2 File Systems and the DCF/2 ΓòÉΓòÉΓòÉ

Based upon extensive comparison tests of the two file systems, our conclusion
is that an HPFS-formatted drive is faster and more efficient than the
equivalent size FAT-formatted drive -- independent of drive size.  You can move
more data, in less time, to an HPFS drive than to the same size FAT drive.

DCF/2 Virtual Disk Units are always formatted using OS/2's High Performance
File System (HPFS) because we feel it is the superior file system.


ΓòÉΓòÉΓòÉ 7. User Reference ΓòÉΓòÉΓòÉ

The User Reference is divided into the following sections. These describe the
functions and operations of the DCF/2 program modules, as well as how to move
files from physical to virtual space.

       o  Startup Manager
       o  Control Program
       o  Ancillary Control Process
       o  Optimize Utility
       o  LED Monitors
       o  Shut Down
       o  DCAT (Disk Compression Analysis Tool)
       o  Moving Files from Physical to Virtual Space


ΓòÉΓòÉΓòÉ 7.1. Startup Manager ΓòÉΓòÉΓòÉ

                            New in DCF/2 Version 1.4!

As OS/2 starts up, it loads the DCF/2 device drivers, starts the DCF/2 control
program and then loads the Presentation Manager or Workplace Shell.  The DCF/2
Startup Manager allows you to access OS/2 system services to do a number of
"system housekeeping" tasks -- before the Presentation Manager loads -- that
you cannot do once PM loads.

Just as OS/2 loads in distinct phases, so does the DCF/2. The DCF/2 Startup has
two phases:  the first is before your virtual disks are available.  The second
phase is after.  Either or both can be interrupted or completely bypassed.
(Should you need to trouble-shoot a situation, this allows you to bring your
system up without the DCF/2 and without having to resort to special boot
disks.)

The DCF/2 Startup Manager places a blue status line or menu at the top of your
screen while the DCF/2 is loading.  Depending upon the default setting you
choose, this will be a blue, single line, status message or a three line menu
[/m] at the top of your screen, or it will be a a slightly larger menu in the
middle of your screen [/M].

As the DCF/2 starts up, the manager gives you an interval of time [/T:seconds]
during which you can to interrupt the startup process before the DCF/2 Control
Processes load.  Your virtual disks are not yet available, but if you need to
CHKDSK the VDU's host or prevent the DCF/2 device drivers from loading, you can
do it now.

The first countdown timer reaches zero and the DCF/2 Control Processes load.
Then the Startup Manager gives you a second interval [/t:seconds] during which
you can interrupt the system startup process.  Because the control processes
are loaded, your virtual disks are available.  If you need to CHKDSK them, you
can do so now.

To activate the manager menu, during either countdown, type 'S.'  The following
keys are "active:"

 Key                 Function
 <ESCAPE>            Skips remaining countdown
 <CONTROL>           Launches an OS/2 command processor
 <SHIFT>             Bypasses further loading of the DCF/2
 <SPACEBAR>          Toggles start/stop of the countdown timer

 Startup Manager default settings are set in your CONFIG.SYS file on the
 following line:

       DEVICE=C:\DCF2\DCF2MGR.SYS  C:\DCF2\DCF2.EXE /A:STARTUP /T:5 /t:5 /m

 The default settings are:  /s /T:5 /t:5 /m

 The optional switches available for the Startup Manager and their functions
 are:

   Switch              Function

   /M                  Big menu

   /m                  Little menu

   /T:[seconds]        Sets the number of seconds to countdown before the DCF/2
                       Control Processes load

   /t:[seconds]        Sets the number of seconds to countdown after the DCF/2
                       Control Processes load

   /S                  "Big Sound" -- enable audible ticks during the countdown

   /s                  "little sound"  -- enable quieter audible ticks during
                       the countdown

   /b                  Sets LED display for monochrome monitor

   /n                  Does not place LED monitors on the Desktop

   /w:[seconds]        Sets number of seconds to pause

 Hint  If you use the DCF2 /+ command to start the DCF/2 processes from an OS/2
       command processor window on the desktop, the Monitor LED will "steal"
       focus. Click on the window's title bar to regain focus.


ΓòÉΓòÉΓòÉ 7.2. Control Program (DCF2.EXE) ΓòÉΓòÉΓòÉ

OS/2 uses the DCF/2 Control program every time your system starts up.  It is
the program executed by either the DCF2MGR.SYS or the CALL statement that the
DCF/2 installation program added to your CONFIG.SYS.  The DCF/2 Control program
in turn starts the DCF/2 Ancillary Control Processes.

You can also use the DCF/2 Control program from an OS/2 command processor to:

       o  Start and stop the DCF/2 control processes
       o  Create virtual disk container files
       o  Temporarily mount or dismount a virtual disk
       o  View VDU drive statistics
       o  Adjust the Monitor LEDs for a monochrome display

 To use the control program, you must either have the DCF2 program directory in
 your path or change to it.  There are only two basic DCF2 command lines.  Each
 has a set of optional parameters or switches which are used to tell the
 program what you want it to do.

   Command             Purpose

   DCF2 /A:            Allows you to do things with the startup of the DCF/2 --
                       set countdown values, sound, menu size, etc.  Controls
                       how your OS/2 system starts up the DCF/2.

   DCF2 /V:            Allows you to manipulate virtual disks -- create them,
                       mount them, view drive statistics, et.

 The command syntax is:

  DCF2 /A: /{required parameter} /[optional parameter] /[optional parameter] ...
                                        or
  DCF2 /V: /{required parameter} /[optional parameter] /[optional parameter] ...

 The following are the parameters available for the DCF2 /A: command:

   Command             Purpose

   /STARTUP            Starts the DCF/2 Control Processes.  Makes your VDUs
                       available.

   /+                  "Shorthand" method to start the DCF/2 Control Processes.

   /w:n                Sets number of seconds to pause

   /M                  Big menu

   /m                  Little menu

   /T:n                Sets the first startup countdown timer to "n" seconds.

   /t:n                Sets the second startup countdown timer to "n" seconds.

   /S                  "Big Sound" -- enable audible ticks during countdown

   /s                  "Little sound"  -- enable quieter audible ticks during
                       countdown

   /b                  Sets LED display for monochrome monitor

   /n                  Does not place LED monitors on the Desktop

   /STATUS             Reports the Status of the DCF/2 Control Processes
                       (currently running or currently not running).

   /SHUTDOWN           Stops the DCF/2 Control Processes.  Your VDUs are
                       unavailable.

   /- (minus)          "Shorthand" method to stop the DCF/2 Control Processes.

 The following table lists the optional parameters available for the DCF2 /V:
 command:

   Command                 Purpose

   CREATE /S:s /F:p        Creates VDU of s=[size in megabytes] and p=[full
                           path and filename of container file]

   MOUNT /F:p /U:x         Mounts VDU container file p=[full path and filename]
                           to VDU drive letter [x:] until you next restart your
                           system.

   DISMOUNT /U:x           Dismounts the container file providing VDU drive
                           letter x:

   STATS /U:x              View VDU drive statistics for VDU drive letter x:

 Note:  There is no colon after the drive letter in the /U: parameter.

 Related topics:

          How to Add a VDU
          How to Delete a VDU
          How to Mount a VDU
          How to Dismount a VDU
          How to View VDU Statistics
          How to Remove the DCF/2
          How to Use "Hot" Keys


ΓòÉΓòÉΓòÉ 7.2.1. How to Add a VDU ΓòÉΓòÉΓòÉ

The following hypothetical system will be used to illustrate how to add or
remove a Virtual Disk:

Test System  We installed the DCF/2 on a system having a physical drive C: and
             a logical partition D:.  We selected C: for the "target" or
             uncompressed drive from which OS/2 runs the DCF/2 programs.  We
             created two VDUs -- one on physical host C: and the other on
             physical host drive D:  The first virtual drive took the first
             available drive letter, E: and the second became F:.

Using the "Test System," we'll go through the steps to add a third VDU.  We'll
give it a size of 100 MB and select D: for its physical host.  We need to:

     1. Create the VDU using the DCF2 /V:CREATE command
     2. Add the VDU drive letter and SET statements to the CONFIG.SYS file
     3. Restart the system to format the new VDU.


ΓòÉΓòÉΓòÉ 7.2.1.1. Create the VDU Container File ΓòÉΓòÉΓòÉ

To run the DCF/2 Control Program, the DCF2 program directory has to be in the
path or we have to change to it.  Then, we use the DCF2 /V:CREATE command:

          DCF2 /V:CREATE /S:100 /F:D:\DCF2\DCF2_G.VDU

 The /S: is the size of the VDU in MegaBytes. The /F: is the full path and file
 specification for the VDU file.  In this example, the full path and filename
 are D:\DCF2\DCF2_G.VDU.  The drive letter is G:, because G is the next
 available drive letter on the test system.


ΓòÉΓòÉΓòÉ 7.2.1.2. Add the VDU Drive Letter and SET Statements ΓòÉΓòÉΓòÉ

We created the VDU file; now we have to allocate a new drive letter and connect
the two.  We do this using the CONFIG.SYS file.  We tell the DCF/2 device
driver to create a third drive letter.  Then we use an environment statement to
connect it with the VDU file.  It may sound ominous, but it really isn't.

To add the VDU drive letter:

       1. Open the CONFIG.SYS file using your favorite text editor
       2. Locate the statement:  DEVICE=C:\DCF2\DCF2PDD.SYS /U:2
       3. Change /U:2 to /U:3
       4. Locate the DCF/2 SET statements which point to E: and F:
       5. Add the SET statement for G:  SET DCF2_VDU_G=D:\DCF2\DCF2_G.VDU
       6. Save the changes to file and exit.

 The DCF2PDD.SYS device and SET statements in the CONFIG.SYS file now look like
 this:

                    DEVICE=C:\DCF2\DCF2PDD.SYS /U:3
                    SET DCF2_VDU_E=C:\DCF2\DCF2_E.VDU
                    SET DCF2_VDU_F=D:\DCF2\DCF2_F.VDU
                    SET DCF2_VDU_G=D:\DCF2\DCF2_G.VDU


ΓòÉΓòÉΓòÉ 7.2.1.3. Restart the Computer ΓòÉΓòÉΓòÉ

To initialize the changes made to the CONFIG.SYS and FORMAT the new VDU, we run
shut down to restart OS/2.

To run OS/2 system shut down, bring up the desktop pop-up menu and select the
shut down menu item.  (OS/2 Warp users can click on the shut down icon on the
tool bar.)


ΓòÉΓòÉΓòÉ 7.2.2. How to Delete a VDU ΓòÉΓòÉΓòÉ

Refer to the hypothetical system described earlier in this section.  If we want
to delete the last VDU, we will have to do the following:

       1. Shut down the DCF/2 control processes
       2. Change the DCF/2 statements in the CONFIG.SYS file
       3. Delete the VDU file
       4. Reboot or restart the computer

 Note:  Deleting a VDU deletes all of the data stored in the VDU.  Be sure to
        make a backup copy of any of the data you do not want to delete
        permanently before proceeding.


ΓòÉΓòÉΓòÉ 7.2.2.1. Shut Down the DCF/2 Control Processes ΓòÉΓòÉΓòÉ

The VDU file is locked open and cannot be deleted while the DCF2 control
processes are running.  (If you try to, you get an error message that the drive
is in use by another process.)  To shut down the DCF/2:

       1. Change to the DCF2 program directory
       2. Type the command, DCF2 /A:SHUTDOWN (or DCF2 /- in 'shorthand').


ΓòÉΓòÉΓòÉ 7.2.2.2. Change the DCF/2 statements in the CONFIG.SYS ΓòÉΓòÉΓòÉ

To remove the VDU drive letter, we edit the CONFIG.SYS:

       1. Open the CONFIG.SYS file in your favorite text editor
       2. Locate the statement:  DEVICE=C:\DCF2\DCF2PDD.SYS /U:3
       3. Change /U:3 to /U:2
       4. Locate the DCF/2 SET statements which point to E:, F: and G:
       5. Remove the statement for G:  SET DCF2_VDU_G=D:\DCF2\DCF2_G.VDU
       6. Save the changes to file and exit.


ΓòÉΓòÉΓòÉ 7.2.2.3. Delete the VDU Container File ΓòÉΓòÉΓòÉ

To protect you from inadvertantly deleting your VDU(s), the DCF/2 sets the
system attribute.  As a result, if are in your DCF2 program directory and type
DELETE *.*, OS/2 deletes the program files but not the VDU(s).

To DELETE the VDU Container File:

       1. Change to the DCF2 program directory
       2. Remove the system attribute from the VDU. Use the command:

                    ATTRIB DCF2_G.VDU -S

       3. Delete the VDU file.  Use the command:

                    DELETE DCF2_G.VDU


ΓòÉΓòÉΓòÉ 7.2.2.4. Restart the Computer ΓòÉΓòÉΓòÉ

To make use of the changes made to the CONFIG.SYS, we run shut down and restart
OS/2 and the DCF/2. The G: drive will no longer exist.


ΓòÉΓòÉΓòÉ 7.2.3. How to Mount a VDU ΓòÉΓòÉΓòÉ

A VDU drive letter and a VDU container file are by default "connected" to each
other by the the environment statements in your CONFIG.SYS file.  For example,

          SET DCF2_VDU_G=D:\DCF2\DCF2_G.VDU

 Using the MOUNT command, you can change the VDU container file associated with
 a particular VDU drive letter temporarily -- until you DISMOUNT it or restart
 your computer, whichever happens first.

 For example, you can MOUNT the one of the DCF/2 VDU SAMPLERS -- SAMPLER1.VDU
 as G:  To use the MOUNT command:

       1. Change to the DCF2 program directory
       2. Type:  DCF2 /V:MOUNT /F:D:\DCF2\SAMPLER1.VDU /U:G

 If you open the DRIVE object for G: or use the DIR command to do a directory
 of G:, you see the contents (5,000+ icons) of Sampler VDU #1.  If you restart
 your system and look at G:, you see the contents of the DCF2_G.VDU file.

 Note:  The MOUNT command requires both the name of the file to be mounted and
        the drive letter to mount it to.


ΓòÉΓòÉΓòÉ 7.2.4. How to Dismount a VDU ΓòÉΓòÉΓòÉ

Restarting your system automatically dismounts a temporarily mounted VDU.  You
can also use a DCF2 command to DISMOUNT a VDU.  To DISMOUNT drive G:,

       1. If it is not in your path, change to the DCF2 program directory
       2. Type:  DCF2 /V:DISMOUNT /U:G

 Note:  The DISMOUNT command requires only the letter of the drive to be
        dismounted. It does not require the name of the file to be dismounted.


ΓòÉΓòÉΓòÉ 7.2.5. How to View VDU Statistics ΓòÉΓòÉΓòÉ

                            New in DCF/2 Version 1.4!

In older versions of the DCF/2, each VDU had a DCF2INFO.CMD to provide you with
statistics on your VDU and Host drive.  To access it, you had to go to a
command line, type the drive letter and \DCF2\DCF2INFO.  No more!

From the Desktop you can now check virtual disk statistics -- things like the
Average Compression Ratio for the data stored on the VDU, virtual and physical
space in use and virtual and physical space available -- as follows:

       1. Place the mouse pointer on the title bar of the VDU's LED monitor
       2. Click the right mouse button
       3. To exit, press <ESCAPE>

 If you prefer to use a command line, you can.  To VIEW the drive statistics
 for G:, you would do the following:

       1. If the DCF2 program is not in your path, change to the DCF2 program
          directory
       2. Type:  DCF2 /V:STATS /U:G
       3. To exit, press <ESCAPE>

 Note:  The /U: must be followed by the VDU drive letter (without a :).

 There are three pop-up windows for each VDU.  Use the <PgUp> and <PgDn> keys
 or the <ENTER> key to change pages.  Use the UP ARROW and DOWN ARROW keys to
 scroll through virtual drives.

          Virtual Space Map -- describes virtual space usage in text and
          graphically (updated in real time)

          Physical Space Map -- describes space usage on the VDU's host
          (updated in real time)

          System Drives Snapshot -- a "snapshot" of your systems drives, their
          format, size and space available -- including the location and size
          of the OS/2 swap file and which drives are currently in use.

 Hint  To go directly to the "Snapshot" screen, place the mouse pointer on the
       title bar of any VDU's LED and press <SHIFT> + <right mouse button>.


ΓòÉΓòÉΓòÉ 7.2.5.1. View VDU -- Virtual Space ΓòÉΓòÉΓòÉ

The View VDU Statistics screen provides both the current ACR (Average
Compression Ratio) and the expected ACR after the VDU is next OPTIMIZED.  It
also allows you to launch an optimize of the drive by pressing <ALT-O>.

Space in use on the virtual disk is described in terms of:

       1. Compressed Bytes in Compressed Elements
       2. Stored Bytes in Stored Elements
       3. Extents & Free Space
       4. VDU After Image Journal

 A compressed element is a block or a unit of compressed bytes.  Stored
 elements or units hold data that either does not compress or that you are not
 compressing in run-time. Extents and free space exist in the drive for
 extended attributes and system use. The "VDU After Image Journal" is
 preallocated space where critical changes are saved during VDU commit
 operations.

 When you optimize a drive with "quick shuffle" enabled, you recover the space
 used by extents and free space.  When you optimize with recompression enabled,
 the number of compressed bytes in compressed elements increases and the number
 of stored bytes in stored elements decreases.

 Hint  Watch the Space Maps get updated in real-time as you optimize a VDU.
       Use the command line to start the DCF2PAKR.  Use the VIEW VDU Statistics
       window to watch the Virtual Space Map change.


ΓòÉΓòÉΓòÉ 7.2.5.2. View VDU -- Physical Host ΓòÉΓòÉΓòÉ

Space in use on the virtual disk's physical host is described by the following
terms:

       1. Bytes in Use (non-VDU)
       2. Bytes in Use by the VDF
       3. Bytes Available on PDU x:

 Bytes in Use refers to the amount of space occupied by files other than the
 virtual disk. Bytes in Use by VDF refers to the amount of space occupied by
 the VDU's container disk file (VDF). Bytes Available on PDU x: (where x is the
 drive letter of the physical disk unit) refers to the remaining physical space
 available for use.


ΓòÉΓòÉΓòÉ 7.2.5.3. View VDU -- System Drives Snapshot ΓòÉΓòÉΓòÉ

Have you ever wanted to see just what drives you have, how big they are and how
much space is available -- without having to go through multiple commands or
pop-up windows?  With the "System Drives Snapshot" you can do just that!

The "snapshot" lists drive letters beginning with C: through Z: (If you don't
have an F: let alone a Z:, it will tell you so!)  It will list for each of the
drives on your system:

          Disk Drive Unit Letter
          Format (FAT, HPFS, VDU on PDU x:, LAN)
          Total Size in MegaBytes
          Total Space Free in MegaBytes

 If a drive is a virtual disk, the DISK DRIVE UNIT field contains VDU rather
 than HPFS or FAT -- VDUs are always HPFS.  This is followed by the Average
 Compression Ratio for the data stored on the VDU and the drive letter of the
 VDU's physical host.

 Drives in use by OS/2 are identified with a "╨┐".  The drive containing the
 OS/2 swap file is identified with an "*".  The swap file size is listed in
 Bytes.


ΓòÉΓòÉΓòÉ 7.2.6. How to Remove the DCF/2 ΓòÉΓòÉΓòÉ

If you want to remove the DCF/2 from your computer completely, the procedure is
much the same as that for deleting a VDU (as described in an earlier section).

       1. Make a backup copy of any of the data you do not want permanently
          deleted from your system
       2. Delete the DCF/2 DLL's
       3. Delete the VDU file(s) and DCF/2 programs
       4. Remove the DCF2 directories
       5. Remove all of the DCF/2 statements in the CONFIG.SYS file
       6. Reboot or restart the computer

 Note:  Deleting a VDU deletes all of the data stored in the VDU.  Be sure to
        make a backup copy of any of the data you do not want to delete
        permanently before proceeding.


ΓòÉΓòÉΓòÉ 7.2.6.1. Delete the DCF/2 DLL's ΓòÉΓòÉΓòÉ

The DCF/2 placed two DLL's in the OS2\DLL directory.  These files are locked
open and cannot be deleted once the PM shell is running.  To delete the DCF/2
DLL's you will have to restart your system and use the DCF/2 Startup Manager:

       1. Run shut down and restart your system
       2. When you see the "DCF/2 startup in. . ." message, hold down the
          <CONTROL> key to launch an OS/2 command processor.
       3. Use the DELETE command to delete the DCF/2 DLL's (where x: is your
          boot drive)

                    DELETE x:\OS2\DLL\DCF2SHUT.DLL
                    DELETE x:\OS2\DLL\SND.DLL

       4. Type EXIT
       5. Hold down the <SHIFT> key to prevent the DCF/2 Control Process from
          loading
       6. Let the PM shell load the Desktop

 Holding the <CONTROL> key down during startup, interrupts that process and
 allows you access to files that you cannot access once PM shell loads.
 Holding down the <SHIFT> key bypasses loading the DCF/2.  This allows you to
 delete DCF/2 programs and VDUs after the PM shell loads.


ΓòÉΓòÉΓòÉ 7.2.6.2. Delete the VDU file(s) and DCF/2 programs ΓòÉΓòÉΓòÉ

Your VDUs may or may not be in the same DCF2 directory as are the DCF/2 program
files.  Before you can DELETE them, you must remove the OS/2 system attribute
from the VDU(s), so that the OS/2 DELETE command will be able to access the
files.

To DELETE the VDU files and programs from a single directory:

       1. Change to the DCF2 directory
       2. Remove the system attribute from the VDU(s) by using the command:

                    ATTRIB *.VDU -S

       3. Remove all the files by using the DELETE command:

                    DELETE *.*

 For each host on which you placed one or more VDUs, change to the host's DCF2
 directory, and repeat steps 2 and 3 to remove the system attribute from and
 delete the VDU(s).


ΓòÉΓòÉΓòÉ 7.2.6.3. Remove the DCF2 directories ΓòÉΓòÉΓòÉ

To remove the DCF2 directory or directories from an OS/2 command prompt, you
have to move up a directory level and then use the REMOVE DIRECTORY command:

       1. CD..
       2. RD DCF2

 You can also remove the DCF2 directory or directories with your mouse pointer
 and the OS/2 DRIVES object:

       1. Open the appropriate DRIVES object
       2. Place the pointer on the object for the DCF2 subdirectory
       3. Click the right mouse button for the pop-up menu
       4. Click the left mouse button on DELETE

 For each host drive on which you placed one or more VDUs, remove the DCF2
 directory.


ΓòÉΓòÉΓòÉ 7.2.6.4. Remove all of the DCF/2 Statements ΓòÉΓòÉΓòÉ

All of the DCF/2 statements added to your CONFIG.SYS file are delimited by
lines and marked with the date-time stamp for the change.  The statements
include:

          DEVICE=x:\DCF2\DCF2PDD.SYS
          DEVICE=x:\DCF2\DCF2CDE.SYS
          DEVICE=x:\DCF2\DCF2MGR.SYS
          CALL=x:\DCF2\DCF2.EXE /A:STARTUP
          Optional system tuning statements preceded with "REM >>"

 The optional tuning statements are not DCF/2-specific.  You may want to leave
 them for reference or later use and remove only the DCF/2 DEVICE and SET
 statements.

 To remove the DCF/2 statements from the CONFIG.SYS file:

       1. Open the file CONFIG.SYS with your favorite text editor.
       2. Locate the DCF/2 statements and REM out or remove them.
       3. Save the changes to the file.
       4. Close the file.

 Hint  If you have not made any changes to your CONFIG.SYS since installing the
       DCF/2, you can avoid having to edit the file manually.  Instead, copy
       CONFIG.!D! to CONFIG.SYS to restore the file as it existed prior to
       installing the DCF/2.


ΓòÉΓòÉΓòÉ 7.2.6.5. Reboot or Restart the Computer ΓòÉΓòÉΓòÉ

To initialize the changes made to the CONFIG.SYS, you must shut down and
restart the computer.


ΓòÉΓòÉΓòÉ 7.2.7. How to Use "Hot" Keys ΓòÉΓòÉΓòÉ

                            New in DCF/2 Version 1.4!

"Hot" keys are combinations of keys that perform operations in a single step,
which otherwise require multiple steps.  The "hot" keys consist of any LED
monitor and the right mouse button -- either alone, or with the <ALT>, <SHIFT>,
or <CONTROL> key.

To use an accelerator key, place the mouse pointer on the title bar of any LED
monitor and using the right mouse button and:

     Key            Function

     < >            (Only the right mouse button.) To "View VDU Statistics" and
                    launch the OS/2 Drives object

     <SHIFT>        To view "System Drives Snapshot"

     <ALT>          To launch DCF/2 online help

     <CONTROL>      To launch the DCAT utility


ΓòÉΓòÉΓòÉ 7.3. Ancillary Control Process (DCF2ACP.EXE) ΓòÉΓòÉΓòÉ

Just as a physical disk unit has a controller, so has a virtual disk.  The
DCF/2 Ancillary Control Process or "DCF2ACP" fulfills this function.  When it
is not running, your virtual disks are not available.

The DCF/2 and its ancillary control process make extensive use of "environment
variables." An environment variable is a command placed in the CONFIG.SYS and
which dictates the way the operating system is going to run and which external
devices it is going to recognise.

The DCF/2 environment variables give you the power to dictate a wide range of
activities -- from customizing the default setting for the "Out of Space
Threshold" warning to turning off run-time compression to achieve "near
physical" performance.

For a complete list of the environment variables and what they do as well as
and their default settings, refer to:

          Environment Variables

 Any DCF/2 Ancillary Control Process error conditions are reported in the
 DCF2ACP.LOG file created in the root of your OS/2 boot drive.  If you
 experience a problem, you may want to enable DCF2ACP logging and debugging to
 a greater degree.  You can do so by removing the REM >> from the DCF2ACP
 logging statement in your CONFIG.SYS and rebooting.

          SET DCF2_ACP_LOGNG=3
          SET DCF2_ACP_DEBUG=3

 The DCF/2 takes advantage of the sophisticated caching mechanisms available
 with the High Performance File System.  Anytime you write data to cache blocks
 -- whether using the DCF/2 of not -- there is the risk that it will be lost
 should the power to the machine be interrupted.  We feel the performance
 benefit caching provides far outweighs this risk.  But, just in case you do
 not share these sentiments, enter the following SET statement in your
 CONFIG.SYS:

          SET DCF2_ACP_MISSION_CRITICAL=1


ΓòÉΓòÉΓòÉ 7.4. Optimize Utility ΓòÉΓòÉΓòÉ

The Optimize Utility is described in detail in the section on  VDU Maintenance,
under the heading:

          Optimizing Virtual Disks


ΓòÉΓòÉΓòÉ 7.5. LED Monitors (DCF2MON.EXE) ΓòÉΓòÉΓòÉ

The DCF/2 monitors are so-called LEDs because they simulate the disk activity
indicator on a physical hard drive.  The DCF/2 places an LED monitor on your
Desktop for each virtual disk unit it finds available at startup.  The LED
monitors have two functions:

          Monitors Indicate Disk Activity
          Monitors Provide Statistical Information


ΓòÉΓòÉΓòÉ 7.5.1. Monitors Indicate Disk Activity ΓòÉΓòÉΓòÉ

The LED monitor icons change color based upon disk activity:

                     LED Monitor Icon Colors & Disk Activity

                                                  ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
                                                  ΓöéColor     ΓöéDisk Activity       Γöé
                                                  Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
                                                  ΓöéRed       ΓöéWrite               Γöé
                                                  Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
                                                  ΓöéBlue      ΓöéRead                Γöé
                                                  Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
                                                  ΓöéGreen     ΓöéCompress            Γöé
                                                  Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
                                                  ΓöéYellow    ΓöéDecompress          Γöé
                                                  ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ


ΓòÉΓòÉΓòÉ 7.5.2. Monitors Provide Statistical Information ΓòÉΓòÉΓòÉ

                            New in DCF/2 Version 1.4!

Using any LED monitor and your mouse pointer, you can "View VDU Statistics" --
with a click of a button:

       1. Place the mouse pointer on the title bar of the VDU's LED monitor.
       2. Click the right mouse button.
       3. Use the <PgDn> to go to the last page, <PgUp> to go to the first
          page, or <ENTER> to cycle through the pages.
       4. To exit, press <ESCAPE>.

 There are three pages of information for each VDU.  In order, these are:

          Virtual Space Map -- describes virtual space usage in text and
          graphically (updated in real time)

          Physical Space Map -- describes space usage on the VDU's host
          (updated in real time)

          System Drives Snapshot -- a "snapshot" of your systems drives, their
          format, size and space available, including the location and size of
          the OS/2 swap file and which drives are currently in use.

 Using the <Up Arrow> and <Down Arrow> keys, you view Virtual Space Maps for
 each of your VDUs.

 Hint  To go directly to the "Snapshot" screen, place the mouse pointer on the
       title bar of any VDU's LED and press <SHIFT> + <right mouse button>.


ΓòÉΓòÉΓòÉ 7.5.3. Optional Parameters for DCF2MON.EXE ΓòÉΓòÉΓòÉ

The following are optional parameters for DCF2MON.EXE. program.  Unlike the
optional parameters used with the DCF/2 Control Program on an OS/2 command
line, these are specified in the parameters box in the LED icon's settings
notebook on the program settings page.

   Parameter           Function

   /U:x                "x" is the VDU drive letter for LED icon

   /x:n                "n" is a decimal that designates the x coordinate
                       location of the LED icon on your Desktop.

   /y:n                "n" is a decimal that designates the y coordinate
                       location of the LED icon on your Desktop.

   /t:seconds          Sets the number of seconds between LED icon refreshes.
                       Increase this if you feel the monitor refreshes are
                       loading your system.  (Applies to certain video
                       adaptors.)

   /w                  Adds the monitor processes to the Window List

   /b                  Sets LED display for monochrome monitor

 Hint  If you stop and start the DCF/2 from an OS/2 command line, and the LEDs
       do not come up, use the OS/2 START command instead of the DETACH command
       to start the monitors so that the VDU View Statistics function is
       available.


ΓòÉΓòÉΓòÉ 7.6. Shut Down ΓòÉΓòÉΓòÉ

As of Version 1.2, the DCF/2 shut down was completely integrated with OS/2's
standard "right mouse button" shut down.  If you have a DCF/2 System Shut Down
icon from a previous version on your desktop, please delete it.

                            New in DCF/2 Version 1.4!

DCF/2 Version 1.4 includes a new feature called "Clean & Close."  After your
virtual disks have been idle for the number of seconds greater than or equal to
the HPFS's "maxage," their cache buffers are flushed and contents commited to
the virtual disk and the disk is marked "clean" and is then closed.

The benefit?  If you use a laptop and your batteries die, "clean & close"
allows your virtual disks to come up clean -- avoiding a lengthy and
unnecessary CHKDSK.  Desktop system users will also appreciate the reduced time
spent running the CHKDSK program on their virtual disks.

Hint  To see what the HPFS maxage is set to on your system, go to an OS/2
      command prompt and use the following command:

            CACHE


ΓòÉΓòÉΓòÉ 7.7. DCAT (Disk Compression Analysis Tool) ΓòÉΓòÉΓòÉ

The DCF/2 comes with a powerful and easy-to-use utility which allows you to
analyze the data on a selected physical or logical drive in terms of the
average compression ratio and the amount of physical disk space you will
recover by storing that data on a DCF/2 virtual disk.

The DCF/2 installation program placed a DCAT icon on your desktop.  The DCAT or
Disk Compression Analysis Tool is an interactive, OS/2 Presentation Manager
application, with full online help (F1, or HELP button).

To run the DCAT, either change to the DCF2 program directory and type:  DCAT,
or place the mouse pointer on the title bar of one of your virtual disk LEDs
and hold down the <CONTROL> key + <right mouse button>.

Note:  You must complete the DCF/2 installation in order to use the DCAT.  It
       requires the DCF/2 Compression/Decompression Engine (DCF2CDE.SYS).


ΓòÉΓòÉΓòÉ 7.8. Moving Files from Physical to Virtual Space ΓòÉΓòÉΓòÉ

You can use any of the DOS, Windows, or OS/2 program utilities with the DCF/2
that you normally use to move, copy and delete files on your system.  There
are, however, some caveats to bear in mind when moving data.

          Using XCOPY & DELETE
          Using the DRIVES Icon
          Applications with Device Drivers


ΓòÉΓòÉΓòÉ 7.8.1. Using XCOPY & DELETE ΓòÉΓòÉΓòÉ

When using XCOPY to copy files into a VDU, we recommend that you include the
'/f' and '/e' command line switches to ensure that the existing file extended
attributes are copied from the physical disk unit.  We also recommend that you
use the /V switch to verify the files as they are copied.  (See the OS/2 online
help for XCOPY for additional switches.)

Using XCOPY and then DELETEing the files in their source location is probably
the safest way to proceed. If you use MOVE bear in mind that if anything goes
wrong you will not have the original copies to repeat the opeation.  The
caution relating to using the Drives icon also applies to this.

Copy files across in manageable amounts.  Test their availability and accuracy
in their new location. Once they have been tested they can be deleted in their
source location, and the space freed up for more VDU storage.


ΓòÉΓòÉΓòÉ 7.8.2. Using the DRIVES Icon ΓòÉΓòÉΓòÉ

The OS/2 DRIVES icon is a powerful Presentation Manager utility.  It not only
copies and moves your files between physical and compressed virtual disk
storage, it simultaneously updates your DESKTOP objects so that they reflect
the necessary drive letter changes, too!

If you have very little physical space available on the VDU's physical host and
use the DRIVES icon, be careful.  The DRIVES icon moves blocks of files by
first copying and then deleting them from their original location.  This can
cause you to run out of physical space on the host drive and may cause OS/2 to
trap.

Note:  Some program objects have references in the LIBPATH, PATH, and DPATH
       statements in your CONFIG.SYS file.  These references may not be updated
       automatically when the program objects are moved.  You may need to
       update references to them in your CONFIG.SYS by hand.


ΓòÉΓòÉΓòÉ 7.8.3. Applications with Device Drivers ΓòÉΓòÉΓòÉ

Some applications (e.g., FaxWorks for OS/2) load device drivers from DEVICE
statements in your CONFIG.SYS file.  In earlier versions of the DCF/2, these
device drivers could not be moved to a virtual disk, because the virtual disk
was not available at the time OS/2 tried to load such device driver.

This version of the DCF/2 includes an early startup feature which makes the
virtual disks available early enough to allow you to move your applications'
device drivers to a virtual disk.  You may need to edit your CONFIG.SYS file so
that the applications' device drivers load AFTER the DCF/2's.

Because the early startup feature does not work equally well on all systems, it
is shipped as an option rather than as the default.  It is enabled by making
two simple edit changes in your CONFIG.SYS file.

Remove the REM >> from in front of the following statement:

          REM >> DEVICE=C:\DCF2\DCF2MGR.SYS C:\DCF2\DCF2.EXE /a:startup

 Add the REM >> to the beginning of the following statement:

          CALL=C:\DCF2\DCF2.exe /A:STARTUP

 If starting the DCF/2 control program from the DCF2MGR.SYS causes your system
 to trap, you will have to start it from the CALL=x:\DCF2\DCF2.EXE statement at
 the end of the CONFIG.SYS and the device drivers for applications stored on
 your virtual disks will need to load from a physical rather than virtual disk.

 Similarly, if your virtual disks are network based, the device drivers for
 applications stored on your virtual disks will need to load from a physical
 rather than a virtual disk.

 This isn't difficult.  It requires a subdirectory on the physical disk that is
 identical to the application's subdirectory on the virtual disk.  The only
 thing in this subdirectory is the application's device driver -- a file with
 the extension ".SYS".  The reference in your CONFIG.SYS for your application's
 device driver points the the subdirectory on the physical rather than the
 virtual disk.


ΓòÉΓòÉΓòÉ 8. VDU Maintenance ΓòÉΓòÉΓòÉ

Maintaining the "health" of your Virtual Disk Unit involves the VDU's physical
host and the VDU itself.  Both the VDU's physical host and the VDU should be
checked periodically using OS/2's disk checking program (CHKDSK).

The VDU should be periodically "purged" of deleted space and its data
"recompressed" and "packed" using the DCF/2's OPTIMIZE utility program
(DCF2PAKR).

For additional information, select a topic from the following:

       o  OS/2's Disk Checking Utility
       o  Checking Physical Space
       o  Checking Virtual Space
       o  Optimizing Virtual Disks
       o  Backing Up Your Data


ΓòÉΓòÉΓòÉ 8.1. OS/2's Disk Checking Utility ΓòÉΓòÉΓòÉ

OS/2's disk checking program (CHKDSK) is used to analyze of the directories and
files on your disk(s):  It reports which file system was used to format the
disk, space usage, and disk errors (if any exist).  If errors are found, the
program is also used to recover from or correct them.

Note:  When CHKDSK fixes errors, it does so by correcting allocation errors and
       removing corrupted files.  It may create special FOUND.000 directories.
       The recovered files may be placed in the FOUND.000 directory or your
       root directory as *.CHK files.

 OS/2 includes both PM and command line versions of the CHKDSK program.  Both
 versions analyze your disk space usage and report disk errors. Both versions
 will allow you to have corrections for errors in file allocation size, lost
 clusters, and extended attributes, written to the disk.

 They do differ, however, especially for HPFS-formatted disks.  The command
 line CHKDSK provides several recovery levels not available with the PM
 version.

 The following two sections describe how to use PMCHKDSK and CHKDSK.  For
 additional information about CHKDSK, please refer to OS/2's Online Help.

 Related topics:

          Using PMCHKDSK
          Using CHKDSK from a Command Line


ΓòÉΓòÉΓòÉ 8.1.1. Using PMCHKDSK ΓòÉΓòÉΓòÉ

To use the PMCHKDSK program, follow these steps:

       1. Open the Drives Icon on your Desktop.
       2. Move the mouse pointer to the drive letter you want to check.
       3. Depress the right mouse button to open the object's pop-up menu.
       4. Move the mouse pointer to the "Check disk" item.
       5. Depress the left mouse button to open the Check Disk box.
       6. Move the mouse pointer to the box labelled "Write Corrections to
          Disk."
       7. Depress the left mouse button to check the box.
       8. Move the mouse pointer to the button labelled "Check."
       9. Depress the left mouse button.
      10. Wait patiently.  Do not stare at the screen:  it will only make the
          time pass more slowly!


ΓòÉΓòÉΓòÉ 8.1.2. Using CHKDSK from a Command Line ΓòÉΓòÉΓòÉ

The file system format of the disk you are checking determines which optional
parameters you can specify when using the CHKDSK program.  These parameters are
listed in the table below:

                          CHKDSK Parameters & Functions

      ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
      ΓöéFile System  ΓöéParameter   ΓöéFunction                      Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      ΓöéFAT & HPFS   Γöé/F          ΓöéFix errors                    Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      ΓöéFAT & HPFS   Γöé/V          ΓöéView all files and directoriesΓöé
      Γöé             Γöé            Γöéon the drive                  Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      ΓöéHPFS only    Γöé/F:0        ΓöéReport errors but do not fix  Γöé
      Γöé             Γöé            Γöéthem                          Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      ΓöéHPFS only    Γöé/F:1        ΓöéReport errors in the disk or  Γöé
      Γöé             Γöé            Γöépartition's current file      Γöé
      Γöé             Γöé            Γöéstructures and fix them       Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      ΓöéHPFS only    Γöé/F:2        Γöé/F:1 and examine for errors   Γöé
      Γöé             Γöé            Γöéand repair other parts of the Γöé
      Γöé             Γöé            Γöédisk or partition that are in Γöé
      Γöé             Γöé            Γöéuse                           Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      ΓöéHPFS only    Γöé/F:3        Γöé/F:2 and examine entire disk  Γöé
      Γöé             Γöé            Γöéincluding space not in use andΓöé
      Γöé             Γöé            Γöécorrect errors                Γöé
      ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ

 To use the CHKDSK program from a command line:

       1. Open an OS/2 command processor (window or full screen).
       2. For FAT-formatted disks, type:  CHKDSK, or
       3. To have corrections for disk errors written to disk, type:  CHKDSK x:
          /F (where x is the drive letter for the disk to be checked).
       4. For HPFS-formatted disks, type:  CHKDSK x: /F:y (where x is the drive
          letter for the disk to be checked and y the HPFS CHKDSK recovery
          level.)

 Note:  While thorough, CHKDSK x: /F:3 will take a VERY long time to complete
        on a large disk.  It is best begun at the end of the day -- when, if it
        requires several hours, it won't matter.

 CHKDSK makes use of caching so it may spend significant time analysing and/or
 correcting your drive without the drive light showing any activity.  Try to
 remember, "Patience is a Virtue."

 For additional information on CHKDSK, please refer to OS/2's Online Help.


ΓòÉΓòÉΓòÉ 8.2. Checking Physical Space ΓòÉΓòÉΓòÉ

The DCF/2 installation procedure edits your CONFIG.SYS file to add the
AUTOCHECK switches for both FAT and HPFS formatted disks if the switches are
not already there.  The switch for the FAT DISKCACHE statement is AC: followed
by your FAT drive letter(s).  The switch for the HPFS CACHE statement is
AUTOCHECK: followed by your HPFS drive letter(s).

In most cases, the only thing you have to do to maintain your physical disk
space is to make sure that you haven't disabled the 'AUTOCHECK' feature.  And,
if you do experience a physical disk problem, make sure you shut down properly
and that the CHKDSK program checks the physical drive thoroughly when your
system restarts.

As described in the previous section, the CHKDSK command and options vary
slightly depending upon the format of the disk being checked.  You will use
CHKDSK /F on FAT-based physical disk units and CHKDSK /F:n on HPFS-based
physical and virtual disk units.

For additional information, please refer to OS/2's Online Help.


ΓòÉΓòÉΓòÉ 8.3. Checking Virtual Space ΓòÉΓòÉΓòÉ

Because a VDU looks physical to OS/2, we can use OS/2's CHKDSK program to
maintain virtual disk units.  The program will correct any space allocation
errors and remove any corrupted files in the virtual disk.

You can run the disk checking program from either an OS/2 prompt or using
OS/2's Drives icon.  From an OS/2 window or full screen, use the command:

      CHKDSK /x: /F (where x is the drive letter for the VDU to be checked).

 If you prefer to "point and click," use the DRIVES icon:

     1. Open OS/2's Drives icon and place the mouse pointer on the VDU's drive
        icon,
     2. Depress the right mouse button to open the object's the pop-up menu,
        and
     3. Select the disk check menu item.
     4. Depress the left mouse button to open the Check Disk box.
     5. Move the mouse pointer to the box labelled "Write Corrections to Disk."
     6. Depress the left mouse button to check the box.
     7. Move the mouse pointer to the button labelled "Check."
     8. Depress the left mouse button.
     9. Wait patiently.


ΓòÉΓòÉΓòÉ 8.4. Optimizing Virtual Disks ΓòÉΓòÉΓòÉ

                            New in DCF/2 Version 1.4!

The optimize utility -- including a new "auto-optimize" feature -- is used to
maintain DCF/2 virtual disks and return space to your virtual disk's physical
host.  The following functions are available:

   Function            Description

   Quick Shuffle       Shuffles free space and space pre-allocated for extents
                       out of the virtual disk

   Purge               Frees up deleted space in the virtual disk.  (Does NOT
                       "purge" data from your VDU!)

   Recompress          Recompresses the data stored in the disk at maximum
                       compression.

   Pack                Packs the compressed data and returns free space to the
                       VDU's physical host.

 The utility is implemented in such a way so as to work either from an OS/2
 command line or from the VDU's desktop LED.  Only the command line interface
 provides you with additional "optional switches," which are used to control
 the optimize level and the impact optimizing your virtual disk(s) will have on
 other jobs running concurrently in the foreground on your system.

 The auto-optimize feature allows you to recover free space and space
 pre-allocated for extents from your virtual disk automatically.  Auto-optimize
 is scheduled to occur only after all VDUs have been "idle" for a default
 period of time AND the amount of free space in a VDU exceeds a threshold
 number of kilobytes in free space and extents.

 The program default settings are: 60 minutes of disk idle time and 1024 Kbytes
 in free space and extents.  You can change the default settings or disable
 this feature altogether using an environment variable.

 Related topic:

          Environment Variables

 To optimize a virtual disk using its LED Monitor:

       1. Place the mouse pointer on the title bar of the VDU's LED monitor.
       2. Click the right mouse button.
       3. Hold down the <ALT> key and press letter O to launch the optimize
          utiity.

 Related topics:

          Special Features
          When to Optimize
          The Optimize Menus
          The Optimize Command Line
          Default Settings
          Adding Optional Switches
          Comments


ΓòÉΓòÉΓòÉ 8.4.1. Special Features ΓòÉΓòÉΓòÉ

Optimizing virtual disks under earlier versions of the DCF/2 required starting
and stopping the DCF/2 control processes.  No more.  In fact with the all new
DCF/2 VDU Optimize Utility, you can:

       o  Change the default optimize level and its "process priority" to fit
          the time you have available and need you have to recover space on the
          VDU's host.

       o  Optimize more than one virtual disk concurrently.

       o  Continue to work on physical and virtual disks not being optimized
          while optimizing other virtual disks.

       o  Interrupt the optimize at anytime by pressing <ESCAPE>.

       o  Change the default setting for auto-optimize -- to optimize free
          space out of your virtual disks during disk idle time -- to suit the
          way you work.

 Attn Windows Users:  When Windows applications startup, they go out and
                      "touch" every drive on your system -- including your
                      virtual disks.

 When Windows "touches" a virtual disk that is being optimized, a message pops
 up.  It gives you the option to interrupt VDU optimization so that the I/O to
 the VDU can continue, or the continue to block I/O to the VDU until the
 optimize completes.

 If you want to run a Windows application while optimizing your virtual disks,
 start it BEFORE you start the optimize.


ΓòÉΓòÉΓòÉ 8.4.2. When to Optimize ΓòÉΓòÉΓòÉ

Your data is compressed to a greater degree when you optimize a virtual disk
with recompress enabled than it is during normal runtime, i.e., when you simply
move data into the virtual disk during an inload or an install.  We suggest you
optimize your virtual disks:

     o  After you inload data to the VDU following the installation of the
        DCF/2.

     o  After you install new programs directly to the VDU.

     o  When you notice a drop in the compression ratio for the data stored in
        the VDU.

     o  When you find the virtual disk's physical disk is running low on space.

     o  After deleting a significant number of files from a VDU

 How often should you optimize your virtual disks?  This will be a matter of
 personal preference.  It will be a function of the "compression rate" and
 "compression level" you select when you install the DCF/2 or using the DCF/2
 Control Program.

 How long will it take?  To optimize a 200 MB Virtual Disk Unit with 190 MB in
 use on a 586/60 class machine will require 20-25 minutes.  Since not all VDUs
 are created and optimized on a Pentium, the following table describes the
 estimated time required to optimize selected-size VDUs on a 486/66 class
 machine:

                   Estimated Time Required to Optimize Your VDU

  ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
  ΓöéVDU Size    ΓöéEstimated Time to Complete            Γöé
  Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
  Γöé100 MB      Γöé15 minutes                            Γöé
  Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
  Γöé200 MB      Γöé30 minutes                            Γöé
  Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
  Γöé500 MB      Γöé75 minutes                            Γöé
  Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
  Γöé1 GB        Γöé2 1/2 to 3 hours                      Γöé
  ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ

 In order to estimate the length of time recompacting the VDU(s) will require
 on your system, refer to the following table.

                 1K Chunks Optimized per Minute by Machine Class

  ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
  ΓöéClass of Machine      ΓöéMinutes per 1K Chunks                 Γöé
  Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
  Γöé486/50 - 586/60       Γöé1 minute per 1K chunks                Γöé
  Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
  Γöé486/25 - 486/50       Γöé3 minutes per 1K chunks               Γöé
  Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
  Γöé386/33                Γöé5 minutes per 1K chunks               Γöé
  Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
  Γöé386/10 - 386/25       ΓöéUp to 10 minutes per 1K chunks        Γöé
  ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ


ΓòÉΓòÉΓòÉ 8.4.3. The Optimize Menus ΓòÉΓòÉΓòÉ

There are two ways to launch the Optimize utility.  The first is by using the
LED icon and your mouse pointer:

       1. Place the mouse pointer on the title bar of the VDU's LED monitor
       2. Click the right mouse button
       3. To begin the optimize, hold down the <ALT> key and press the O key

 The second way to launch the Optimize utility is from an OS/2 command line,
 using the DCF2PAKR command. When you start the optimize utility on a virtual
 disk using the command line, you can also access the program's built-in HELP
 sub-system.  The Virtual Disk Unit Optimize Screens are described below:

     1. The first screen requests the letter of the drive to be optimized.  You
        can:

          a. Enter the drive letter of the virtual disk to be optimized, or
          b. Press "?" to access help screens, or
          c. Press ESCAPE to exit.

     2. The second screen asks you to verify your selection.  You can:

          a. Press ENTER to continue, or
          b. Press ESCAPE to return to the the drive selection screen.

     3. The program reports the optimization is complete including the number
        of bytes recovered by the process.  Press ENTER to exit.


ΓòÉΓòÉΓòÉ 8.4.4. The Optimize Command Line ΓòÉΓòÉΓòÉ

To run the optimize utility from the a command line, first make sure that the
DCF2 directory is either in your path or that you have changed to it; then
type:

      DCF2PAKR /V:x [/O:n /P:i /p:j]

 where "x" represents the letter of the virtual disk to be optimized and
 optional switches are enclosed in square brackets.  (If you forget to specify
 the VDU drive letter on the command line, don't panic.  You have an
 opportunity to enter it on the optimize menu.)


ΓòÉΓòÉΓòÉ 8.4.5. Default Settings ΓòÉΓòÉΓòÉ

The program's default setting is to "Quick Shuffle" space out of the virtual
disk.  It does not purge or recompress or pack the data on your virtual disk.
It returns less space to the VDU's physical host than a "full" optimize, but
also requires far less time to complete.

When time permits, you should optimize your virtual disks using at level /O:1
in order to return the maximum amount of space possible to the virtual disk's
physical host.  This may be once a week or once a month -- at whatever interval
best suits your needs.

The default settings for the DCF2PAKR are:

      DCF2PAKR /V:x [/O:0 /P:2 /p:10]


ΓòÉΓòÉΓòÉ 8.4.6. Adding Optional Switches ΓòÉΓòÉΓòÉ

The optional switches described in the table below allow you to specify which
of the DCF2PAKR operations are performed when you optimize the virtual disk and
what priority OS/2 allocates this DCF/2 process, relative to other jobs running
on your system.

                  Optional Switches, Ranges & Default Settings

      ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
      ΓöéSwitch    ΓöéFunction            ΓöéAccepted Values     ΓöéDefault   Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/O:n      ΓöéSpace Recovery      Γöé0 through 4         Γöé/O:0      Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/P:i      ΓöéProcess Priority    Γöé1 through 4         Γöé/P:2      Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/p:j      ΓöéProcess Delta       Γöé0 through 10        Γöé/p:10     Γöé
      Γöé          ΓöéPriority            Γöé                    Γöé          Γöé
      ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ


ΓòÉΓòÉΓòÉ 8.4.7. Optimize Level Switches ΓòÉΓòÉΓòÉ

The /O:n switch specifies which of the DCF2PAKR operations should be executed.
The default value for "n" is 2 (recompress and pack data, do not purge).  Value
"n" must be either 1, 2, 3 or 4.  These values are as described in the
following table:

                             Optimize Level Switches

      ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
      ΓöéValue     ΓöéFunction                                          Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/O:0      Γöé[Default] Quick Shuffle.  Shuffles free space out Γöé
      Γöé          Γöéof the virtual disk                               Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/O:1      ΓöéFull optimize:  Purge, recompress & pack          Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/O:2      ΓöéNo purge.  Recompress & pack only                 Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/O:3      ΓöéPurge & pack.  No recompress                      Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/O:4      ΓöéPack only.  No purge or recompress                Γöé
      ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ

 Related topics:

          Optimize Priority Switches


ΓòÉΓòÉΓòÉ 8.4.8. Optimize Priority Switches ΓòÉΓòÉΓòÉ

The are two switches used to set the priority OS/2 will give to the DCFPAKR
operations  relative to other jobs running on your system at the same time.
These are:  /P:i and /p:j.

The DCF2PAKR /P: default setting is 2 -- server priority.  If no other job
processes will be running when you run DCF2PAKR, you may want to increase its
priority settings to /P:3 and its delta level within that priority to /p:10.

Whenever possible, run the optimize as a foreground job.  It will take 3 to 4
times longer to complete if it is run in the background.

Caution  Be extremely careful with regard to setting the priority  of the /P:
         switch to either time critical (3) or idle (1).  Time critical
         priority (3) is higher than server priority (4) and a job running at
         time critical will have a significant impact on other foreground jobs.
         Conversely, jobs running at idle time priority (1) are only serviced
         when there is nothing else to be serviced and can take a very long
         time!

 Related topics:

          Priority Level Switches
          Delta Level Switches


ΓòÉΓòÉΓòÉ 8.4.9. Priority Level Switches ΓòÉΓòÉΓòÉ

The /P:i switch determines how often OS/2 services requests from the DCF2PAKR
program, i.e., the priority for that process.  The default value for "i" is 4
(server priority).  Value "i" must be either 1, 2, 3 or 4.  These values are as
described in the following table.

                             Priority Level Switches

      ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
      ΓöéValue     ΓöéFunction                                          Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/P:1      ΓöéIdle time.  The job is only serviced when your    Γöé
      Γöé          Γöésystem is completely idle.                        Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/P:2      Γöé[Default] Normal.  The job is serviced at regular Γöé
      Γöé          Γöéintervals.                                        Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/P:3      ΓöéTime Critical.  The job is serviced more often    Γöé
      Γöé          Γöéthan any other job.                               Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/P:4      ΓöéServer.  The job is serviced more often than thoseΓöé
      Γöé          Γöéat normal but less often than those at            Γöé
      Γöé          Γöétime-critical priority.                           Γöé
      ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ


ΓòÉΓòÉΓòÉ 8.4.10. Delta Level Priority Switches ΓòÉΓòÉΓòÉ

If you do not specify a process priority using /P:i switch, you probably will
not use the /p:j switch.

The /p:j switch determines the thread priority within the process priority.
The default value for "j" is 10 (middle high).  Value "j" must be a whole
number between 0 and 10.  These values are described in the following table.

                              Delta Level Switches

      ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
      ΓöéValue     ΓöéFunction                                          Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/p:0      ΓöéLow priority delta -- everything else happens     Γöé
      Γöé          Γöéfirst!                                            Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/p:1...9  ΓöéPriority delta increases as the value increases.  Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/p:10     Γöé[Default] Middle high priority delta.             Γöé
      ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ


ΓòÉΓòÉΓòÉ 8.4.11. Comments ΓòÉΓòÉΓòÉ

The DCF/2 attempts to keep relational extents available during inloads (i.e.,
when you first move new data into the compressed volume).  These extents form
free space which should be recovered after major data inloading, by using the
optimize utility.

Deleted HPFS files are not really deleted from your virtual disk units until
the deleted space is purged from the VDU using the DCF2PAKR command followed by
either the /O:1 or /O:3.  This means that these files can be undeleted using
HPFS undelete utilities up until such time as you run the DCF2PAKR with purging
enabled.  Remember, however, that deleted space is not recovered for use until
it is PURGED from the VDU.

Because the DCF/2 supports HPFS undelete utilities up until you PURGE the
virtual disk, deleting files from the VDU actually increases the size of the
virtual disk file -- the increase is due to the HPFS writing new FNODES and
bitmaps.

The size of the VDU file also increases during the first part of a purge
operation -- as a temporary file is built.  This space is returned to the VDU's
host once purge completes.

If the physical space on a VDU's host falls below the 3 MB threshold and you
need to free up space,

          Do NOT purge the virtual disk.

          Do NOT delete lots of small files from the virtual disk.

          Do delete files from the host drive if possible.

          If there are no files on the host which can be deleted, delete
          several (5-10 MB) large files from the VDU.

 During normal run-time, you may elect to set your background compression rate
 to 0, 1, 2 or 4, in order to minimize the time your system spends compressing
 and thereby boost performance.  Doing so, increases amount of stored,
 uncompressed, or semi-compressed elements in the VDU and lowers compression
 ratio for the data stored in the VDU.  When you optimize the VDU with
 recompression enabled, freed space is returned to the VDUs host all at once.


ΓòÉΓòÉΓòÉ 8.5. Backing Up Data ΓòÉΓòÉΓòÉ

The DCF/2 virtual disk units offer you a great deal of backup flexibility. You
can back up the VDU's host drive, and, in so doing, create an "image" back up
of the VDU container file.  Or, you can back up the individual files on the
VDU, file-by-file.

In either case, the important point is that you do back up your data (both
physical and virtual).  Disk drives are mechanical things -- eventually they
are going to fail; so don't put this important system management function off
until it's too late!

Related topics:

          Image Back Up
          File-by-File Back Up


ΓòÉΓòÉΓòÉ 8.5.1. Image Back Up ΓòÉΓòÉΓòÉ

You can back up the VDU container file itself and have an 'image' backup of the
compressed volume.  Before you do an 'image' backup, you must stop the DCF2
processes.  Otherwise, the VDU container file is locked open.  (If you get an
error doing a back up of the VDU's host drive, this is the most likely cause.)

To stop the DCF2ACP, change to the DCF2 program directory and use the following
command:

          DCF2 /-

 After you complete an image back up, restart the DCF2ACP using the following
 command:

          DCF2 /+


ΓòÉΓòÉΓòÉ 8.5.2. File by File Back Up ΓòÉΓòÉΓòÉ

You can back up the individual files in the VDU and have "file-by-file" backup
of your compressed data.  This method provides an uncompressed copy of each
file in the VDU's compressed storage.  Unlike the image back up, during a
file-by-file back up, the DCF2ACP remains running.


ΓòÉΓòÉΓòÉ 9. Troubleshooting ΓòÉΓòÉΓòÉ

The following sections describe the most common problems and what to do.

The first rule is:  Don't panic.  Using the tools you have on hand, you can
recover from almost any situation.

The topics covered include:

       o  Logfiles
       o  Installation Fails
       o  VDU Drive Letter Incorrect
       o  VDU Does Not Autoformat
       o  Long Low Beep-Beep During Initialization
       o  System Hangs or Traps
       o  Drive Inconsistencies
       o  Root Directory Not Found
       o  Out-of-Space Warning
       o  Virtual Disk Size Increases When Files are Deleted
       o  Shut Down Doesn't Work
       o  Miscellaneous
       o  Contacting Technical Support


ΓòÉΓòÉΓòÉ 9.1. Logfiles ΓòÉΓòÉΓòÉ

The first place to look to diagnose the cause of a suspected problem is the
logfile DCF2ACP.LOG in the root of your boot drive.  The logfile is created
automatically by the DCF/2.  If you delete it -- which you will want to do from
time to time -- it will be recreated the next time you startup the DCF/2.

In some cases, you may need more detailed log information.  When you installed
the DCF/2, it installed in your CONFIG.SYS file logging and debug statements
for the DCF2ACP.  To enable logging permanently, you can remove the "REM >>"
from in front of both statements.

          SET DCF2_ACP_LOGNG=3
          SET DCF2_ACP_DEBUG=3

 Before calling for technical support, please have a copy of the DCF2ACP.LOG
 available.  You may be asked to fax a copy of it to us.  If the file covers
 several days, it will not be necessary to send all of the pages -- usually the
 last few entries will be all that are necessary.


ΓòÉΓòÉΓòÉ 9.2. Installation Fails ΓòÉΓòÉΓòÉ

If you installed the DCF/2 from a temporary directory on your hard drive, make
sure the name of the temporary directory is not "DCF2."  If it is, make a new
temporary directory using some other name (e.g.,D:\tmp), copy the files to the
new directory and delete the old one.  Run the DCF/2 installation program from
the new temporary directory.

If you are running the installation program from a command prompt instead of
the DRIVEs object, make sure that you are using an OS/2 command processor.  The
DCF/2 installation program cannot be run from a DOS window or full screen.


ΓòÉΓòÉΓòÉ 9.3. VDU Drive Letter Incorrect ΓòÉΓòÉΓòÉ

The first VDU will take the first physical drive letter available on your
system.  Remember that network drives are logical not physical.  If network
drives are enabled when the DCF/2 installation program is run, the first VDU
will take an incorrect drive letter.

          For example, say your system has a physical drive C:, logical D:,
          network drives E: and F:.  If you have not logged off of your network,
          the DCF/2 would assume that the first available drive letter is G: rather
          than E:.  Therefore, if you have LAN software running, you need to
          logoff prior to running the DCF/2 installation program.

 If you have completed the installation process and only later realized that
 you had not logged off of your network, you can make the necessary changes to
 correct the drive letter manually.  Do the following:

       1. Edit the VDU's SET statement in your CONFIG.SYS file to reflect the
          correct drive letter if it does not.

       2. Change to the DCF2 program directory.  Remove the system attribute
          from the VDU file:

               ATTRIB *.VDU -S

       3. Rename the VDU file to match that of its environment statement in the
          CONFIG.SYS

       4. Reboot the system.

 Return to the example of the system with physical C: and logical D:, on which
 the first VDU should be E: and the second F: -- but, because we hadn't logged
 off of the network before running the DCF/2 installation program, the first
 VDU took drive letter G: and the second H:.

 The incorrect statements inserted in the CONFIG.SYS look like this:

          DEVICE=C:\DCF2\DCF2PDD.SYS /u:2
          SET DCF2_VDU_G=C:\DCF2\DCF2_G.VDU
          SET DCF2_VDU_H=D:\DCF2\DCF2_H.VDU

 First, we edit each SET statement in the CONFIG.SYS to reflect the correct
 drive letters, E: and F: and save the changes.  The corrected statements look
 will this:

          SET DCF2_VDU_E=C:\DCF2\DCF2_E.VDU
          SET DCF2_VDU_F=D:\DCF2\DCF2_F.VDU

 Next, we change to the DCF2 program directory on drive C: and remove the
 system attribute from the VDU:  ATTRIB *.VDU -S

 Now, we rename the file:  RENAME DCF2_G.VDU DCF2_E.VDU

 We repeat the above two steps for the second VDU -- changing to the DCF2
 directory on D:, removing the system attribute and renaming the file to be, in
 this case, DCF2_F.VDU.

 Finally, we shutdown and restart the system to initiate the changes we've
 made.


ΓòÉΓòÉΓòÉ 9.4. VDU Does Not Autoformat ΓòÉΓòÉΓòÉ

Each VDU must have an environment statement in the CONFIG.SYS file which
provides the full path for the VDU's container file.  If this statement is
missing or incorrect, the DCF/2 cannot find the file.

This situation is most likely to occur if you create additional VDUs after
having run the DCF/2 installation program and forget to either increment the U:
number following the DCF2PDD.SYS or to add an environment statement for the
VDU.  (Check, too, for typographical errors.)

Check to make sure that the environment statement does in fact exist and that
the drive association is correct, i.e., it points to a valid VDU file in the
right directory on the right Host.  You can do this by looking at the
statements the install program placed in your CONFIG.SYS file, or you can use
the following OS/2 command: SET

In either case, your should find a statement that resembles the following for
each VDU:

          SET DCF2_VDU_x=d:\DCF2\DCF2_x.VDU

 In the above statement, x is the VDU's drive letter and d is the VDU's host's
 drive letter

 Refer to the foregoing example if you find you have made a mistake and need to
 correct either the VDU's file name and/or the environment statement(s).
 Remember when checking for valid files in directories on the host drive(s)
 that the DCF/2 sets the system attribute so that they cannot be inadvertently
 deleted.

 So, to locate the virtual disk files on each physical drive with a DCF2
 directory, use the OS/2 command:

          DIR x:\DCF2\*.VDU /A


ΓòÉΓòÉΓòÉ 9.5. Beep-Beep-Beep Signals ΓòÉΓòÉΓòÉ

Multiple beep-beep-beeps signal that an error message is being written to the
DCF2ACP.LOG file in the root of your boot drive.  Check the log file for error
messages.

A long low beep during system startup can indicate a failure to place a lock on
shared memory, due to the way in which OS/2 allocates memory during system
startup.

The solution is to either move the DCF/2's CALL= statement from the end of your
CONFIG.SYS file to your STARTUP.CMD, or to reduce or increase the cache sizes
for either or both the HPFS cache and the FAT diskcache.

In some cases, the order in which various DEVICES load in the CONFIG.SYS can
affect OS/2's memory allocation during startup.  Since systems differ, you may
find it helpful to experiment with the order in which DEVICES load on your
system.


ΓòÉΓòÉΓòÉ 9.6. System Hangs or Traps ΓòÉΓòÉΓòÉ

If your system fails to startup correctly, i.e. it hangs before or during VDU
initialization, or as the workplace shell loads, you need to try to isolate the
cause.

On some systems, the DCF/2 early startup -- using the DCF2MGR.SYS during OS/2's
system initialization -- can cause the system to trap.  Check you CONFIG.SYS
file to determine if the DCF2MGR.SYS is enabled.  If it is, disable it.

Note:  The DCF2MGR.SYS is an option enabled in your CONFIG.SYS only when the
       "REM >>" preceding it has been removed and a corresponding "REM >>" has
       been added to the beginning of the DCF/2 CALL statement at the end of
       the CONFIG.SYS file.

 In any other case, to isolate the cause of a trap or hang, do the following:

       1. Reboot the system.

       2. At the first DCF/2 Startup message, hold down the <SHIFT> key to
          bypass loading the DCF/2 control processes.

       3. If the system still hangs, do the following:

            a. Reboot the system.
            b. As soon as the OS/2 logo box(es) come up, hold down the <SHIFT>
               key to bypass loading the DCF/2 device drivers.
            c. If the system still hangs, you have at least elimated the DCF/2
               as the cause.  The hang may be caused by the order in which
               devices are loaded in the CONFIG.SYS.  Experiment with the order
               in which various (especially newly installed) devices are
               loaded.

       4. If eliminating the DCF/2 also eliminated the hang, do the following:

            a. Reboot the system.
            b. At the first DCF/2 Startup message, hold down the <SHIFT> key to
               bypass DCF/2 loading.
            c. Run CHKDSK /F on all host drives followed by CHKDSK /F on all
               VDUs. If your boot drive is a host run CHKDSK /F from floppies
               as recommended by IBM.
            d. Use the DCF2PAKR to optimize and repair each of your virtual
               disks. Type:

                                       DCF2PAKR /V:x /O:2

            e. Repeat this step for each VDU.
            f. Shutdown and restart the system to enable your VDUs.

 System startup should continue.  The VDUs should initialize and all should be
 back in order.

 If problems persist, check the DCF2ACP.LOG file in the root of your boot
 drive, and contact technical support.


ΓòÉΓòÉΓòÉ 9.7. Drive Inconsistencies ΓòÉΓòÉΓòÉ

The prescribed remedy if you suspect a serious problem is to do the following:

       1. Run CHKDSK /F:2 on the physical host drive three times.  (You may
          need to do this from floppy.)
       2. Run CHKDSK /F:3 on the physical host drive at least one time.
          (Twice, maybe.)
       3. Startup the DCF/2 and repeat steps 1. and 2. for each virtual disk
          unit.

 Because of the time involved, you may want to write a simple batch file, e.g.
 CHKVDU_M.CMD, that you can run at night.  It might look like the following for
 Host drive h: and VDU x: :

          @echo off
          DCF2 /-
          CHKDSK h: /F
          CHKDSK h: /F
          CHKDSK h: /F
          CHKDSK h: /F:3
          CHKDSK h: /F:3
          DCF2 /+
          CHKDSK x: /f
          CHKDSK x: /f
          CHKDSK x: /f
          CHKDSK x: /F:0
          CHKDSK x: /F:0
          EXIT

 Because it is possible to run CHKDSK multiple times with different results
 each time, it is important to run it until it reports no more errors or
 corrections.


ΓòÉΓòÉΓòÉ 9.8. Root Directory Not Found ΓòÉΓòÉΓòÉ

Do not panic.  This occurs infrequently -- generally after a severe system
crash.

Allow CHKDSK /F to run and repair any damage.  In some cases, this can require
several hours.  Because of the "iterative" nature of the program, you should
then run it again and again until it no longer reports errors.  You may have
some work to do to rename the FOUND* directories and *.CHK files, but your VDU
will be intact.

In extreme cases, it may be necessary to restart or reboot your computer
system.  We have had instances where it looked as if a drive had been lost only
to restart the system and find it still there and intact.

Following the CHKDSKs, /V:x /O:2 to recompress all of the data stored on the
VDU.  Do not use the optimize PURGE option in this case.  The objective here is
not to recover space; it is to decompress and recompress all of the elements of
data on the VDU and, if necessary, to correct the VDU's DAT (disk allocation
table).


ΓòÉΓòÉΓòÉ 9.9. Out-of-Space Warning ΓòÉΓòÉΓòÉ

When the space available on a virtual disk's physical host falls below a
threshold number of MegaBytes, the DCF/2 throws up a big, red warning message.
Do the following:

       1. Do NOT ignore the warning.

       2. If you have data on the physical disk that you can delete, do this
          first.

       3. If there is nothing on your physical disk that you can delete, delete
          a few large files from the virtual disk.  DO NOT DELETE LOTS OF SMALL
          FILES.

       4. Run DCF2PAKR /V:x /O:0 to shuffle free space out of the virtual disk.

       5. Now you should have sufficient free space to purge deleted space from
          the virtual disk.  Run DCF2PAKR /V:x /O:1 (to purge, recompress and
          pack) or /O:3 (to purge and pack).

 At the Out-of-Space Warning, you still have room to manuever.  If you ignore
 the warning and the space available on the virtual disk's host approaches
 zero, the DCF/2 will suspend all writes to the virtual disk until you free up
 physical space on the host by repeating the steps outlined above.

 Remember DIR and CHKDSK will report free space on a VDU based upon the
 capacity OS/2 believes the disk has.  If there is no more space available on
 the virtual disk's physical host, there is no more space available in the
 virtual disk either -- regardless of the capacity OS/2 thinks it has.  Check
 your drive statistics on a regular basis.


ΓòÉΓòÉΓòÉ 9.10. Virtual Disk Size Increases When Files are Deleted ΓòÉΓòÉΓòÉ

Because the DCF/2 supports HPFS undelete utilities up until you PURGE the
virtual disk, deleting files from the VDU actually increases the size of the
virtual disk file -- the increase is due to the HPFS writing new FNODES and
bitmaps.

If the physical space on a VDU's host falls below the 3 MB threshold and you
need to free up space,

       1. Do NOT purge the virtual disk.  (Purge causes a temporary increase in
          size.)

       2. Do NOT delete lots of small files from the virtual disk.

       3. Do delete files from the host drive if possible.

       4. If there are no files on the host which can be deleted, delete
          several (5-10 MB) large files from the VDU, then run pack or purge.


ΓòÉΓòÉΓòÉ 9.11. Shut Down Doesn't Work ΓòÉΓòÉΓòÉ

If your system does not shut down through to the final Ctl-Alt-Del box, it may
or may not be related to the DCF/2.  To determine if it is, do the following:

       1. Restart your computer.
       2. Hold down the <SHIFT> key as the OS/2 logo box(es) comes up to bypass
          loading the DCF/2 device drivers.
       3. Continue to hold the <SHIFT> key until the Desktop is up.
       4. Run shut down.
       5. If shut down still fails, you at least know now that it is not due to
          the DCF/2.

 If your system shuts successfully when you eliminate the DCF/2, check to see
 if the DCF/2's SND.DLL and DCF2SHUT.DLL are missing, or if reinstalling OS/2
 or a new application has changed the ordering of directories in the PATH and
 LIBPATH statements in your CONFIG.SYS file.  Do the following:

       1. Verify that the SND.DLL and DCF2SHUT.DLL are in the OS2\DLL
          sub-directory on your boot drive.  If they are there,

            a. Check the PATH and LIBPATH statements in your CONFIG.SYS file,
               to make sure that the OS2\DLL sub-directory appears before
               references to the MMPM sub-directory. Change the PATH and
               LIBPATH statements if necessary.
            b. Reboot.

       2. If the SND.DLL and DCF2SHUT.DLL are not there, reinstall the DCF/2 --
          making sure to place a check in the box labelled, "UPDATE/REGISTER
          ONLY."

 If the problem persists, contact Proportional Software Technical Support.

 Related topic:

          Contacting Technical Support


ΓòÉΓòÉΓòÉ 9.12. Miscellaneous ΓòÉΓòÉΓòÉ

VDU Statistics Incorrect

VDU statistics are updated only after an optimize completes and shared memory
has been updated.  If optimize completes and the statistics seem incorrect,
stop and then restart the DCF/2 control processes.  VDU statistics should then
be correct.

4OS2

If you are running 4OS2, make sure you are running the most current version.
Older versions of 4OS2 have been known to produce strange messages.  Some users
have reported problems shutting down when using 4OS2.


ΓòÉΓòÉΓòÉ 9.13. Contacting Technical Support ΓòÉΓòÉΓòÉ

Telephone technical support is available to registered users only.  Please have
your license number handy as well as a copy of the DCF2ACP.LOG file if
appropriate.  Telephone technical support is available Monday through Friday
between 9 a.m. to 4 p.m Mountain Time.  The telephone number is [phone].

Online technical support is available to both registered and unregistered users
through the Proportional Software OS2BBS CForum (OS2DCF2 via IBM TalkLink and
Advantis) and through the Proportional Software Vendor Forum on CompuServe (GO
OS2AVEN).  Our internet address is [e-mail].

For Technical Support in Europe check for contact details via the OS2 Vendors
Forum on Compuserve (GO OS2AVEN), or the supplier of your copy.


ΓòÉΓòÉΓòÉ 10. Glossary of Terms ΓòÉΓòÉΓòÉ

The glossary provides definitions for commonly used terms as they relate to the
DCF/2.

Ancillary Control Process (DCF2ACP)

Just as a physical disk unit has a controller, so do our virtual disks. The
"ACP" is the virtual disk's controller.  When the DCF2ACP is stopped, it is
analogous to pulling your physical disk's controller out of your system box.
You cannot access compressed data on a VDU if the DCF2ACP is not running.

DAT

The DAT is the Disk Allocation Table  -- not a digital analogue tape.  The DAT
records the location of each compressed or stored element, as well as free
space available, on the VDU.

"Dirty"

The term "dirty" is used to describe the state of a physical or virtual drive
when the drive has been written and then shut down by a means other than
running OS/2 system shut down.

Typically, this happens if you switch off the computer without running shut
down first.  It can happen as the result of a power failure or brownout.  It
can also happen as the result of an operating system trap or hang.

A drive that is "dirty" must be CHKDSKed prior to its being available for use.
The AUTOCHECK and AC switches in the HPFS and FAT statements in CONFIG.SYS
enable this at start up time automtically.

DTE

A DTE is an entry in the Disk Allocation Table.

Environment Variable

An environment variable is a command placed in the CONFIG.SYS that dictates to
the way the operating system is going to run and what external devices it is
going to recognise.

Host Drive

The host drive is the uncompressed, physical drive on which a DCF/2 "Virtual
Disk Unit"  or VDU resides.

On-the-fly Data Compression

An on-the-fly data compression product creates a special file, which serves as
a container for compressed data.  When the an application requests data stored
in this way, the data is automatically compressed or decompressed "on-the-fly."
The user does not have to execute a command to "unzip" or "unpak" the data
requested.

Physical Device Driver (DCF2PDD.SYS)

The DCF/2 physical device driver creates template block devices -- virtual disk
units.  The /U:n following the DEVICE= statement in the CONFIG.SYS determines
how many virtual disk units are created at system startup.  These look and
behave, as far as OS/2 is concerned, like real physical disk drives.

Target Drive

The target drive is the uncompressed drive to which the DCF/2 program files are
copied during the installation and from which OS/2 runs DCF/2 programs.

Virtual Disk Unit or VDU

"Virtual Disk Unit" is the term we use to describe a DCF/2 compressed drive. It
looks like a "real" or "physical" drive to OS/2.

In reality, a virtual disk unit is a simple, flat file with no EAs (extended
attributes), which provides storage for your data in compressed format.
Because it is just a flat file, it can reside on any device supported by OS/2
-- be that FAT, HPFS, network or removable media.


ΓòÉΓòÉΓòÉ 11. Appendix ΓòÉΓòÉΓòÉ

 The Appendix contains the following sections:

       o  DCF/2 Command Reference
       o  Startup with more than 5 Virtual Disks
       o  Tip & Techniques
       o  Cache Considerations
       o  20 Questions About DCF/2
       o  Trademarks, Copyrights & Acknowledgements


ΓòÉΓòÉΓòÉ 11.1. DCF/2 Command Reference ΓòÉΓòÉΓòÉ

 Listed below are the commands available for the following DCF/2 programs:

       o  Control Program -- Startup
       o  Control Program -- Virtual Disks
       o  Environment Variables
       o  Device Driver Priority
       o  Optimize Utility
       o  Monitor Program


ΓòÉΓòÉΓòÉ 11.1.1. Control Program -- Startup ΓòÉΓòÉΓòÉ

The command syntax for DCF2 /A:

 DCF2 /A: /{required parameter} /[optional parameter] /[optional parameter] ...

The following are parameters available for the DCF2 /A: command:

   Parameter           Purpose

   /STARTUP            Starts the DCF/2 Control Processes.  Makes your VDUs
                       available.

   /+                  "Shorthand" method to start the DCF/2 Control Processes.

   /w:n                Sets n = number of seconds to pause

   /M                  Big menu

   /m                  Little menu

   /T:n                Sets the first startup countdown timer to "n" seconds.

   /t:n                Sets the second startup countdown timer to "n" seconds.

   /S                  "Big Sound" -- enable audible ticks during countdown

   /s                  "Little sound"  -- enable quieter audible ticks during
                       countdown

   /b                  Sets LED display for monochrome monitor

   /n                  Do not place LED monitors on the Desktop

   /STATUS             Reports the Status of the DCF/2 Control Processes
                       (currently running or currently not running).

   /SHUTDOWN           Stops the DCF/2 Control Processes.  Your VDUs are
                       unavailable.

   /-(minus)           "Shorthand" method to stop the DCF/2 Control Processes.


ΓòÉΓòÉΓòÉ 11.1.2. Control Program -- Virtual Disks ΓòÉΓòÉΓòÉ

The command syntax for DCF2 /V is:

 DCF2 /V: /{required parameter} /[optional parameter] /[optional parameter] ...

The following table lists the optional parameters available for the DCF2 /V:
command:

   Parameter               Purpose

   /CREATE /S:n /F:p       Creates container file for a VDU of n=[size in
                           megabytes] and p=[full path and filename of
                           container file]

   /MOUNT /F:p /U:x        Mounts VDU container file p=[full path and filename]
                           to VDU drive letter x: until you next restart your
                           system.

   /DISMOUNT /U:x          Dismounts VDU drive letter x:

   /STATS /U:x             View VDU drive statistics for VDU drive letter x:


ΓòÉΓòÉΓòÉ 11.1.3. Environment Variables ΓòÉΓòÉΓòÉ

                            New in DCF/2 Version 1.4!

An environment variable is a command placed in the CONFIG.SYS that dictates the
way the operating system is going to run and what external devices it is going
to recognise.

When your CONFIG.SYS file was updated during the installation of DCF/2 Version
1.4, the following environment statements were added.  In most cases, they are
preceeded by "REM>>".  To enable a setting, remove the "REM>>", save the change
and restart your computer system.

The following is a list of the Environment Variables provided with the DCF/2.

 SET DCF2_ACP_FOREGROUND_COMPRESS_RATE=5
    Data on a VDU is stored in "elements".  The foreground compression rate
    tells the DCF/2 to how many elements to compress before storing the next
    element for compression later.

      Minimum = 0
      Maximum = 100
                The default setting is 5 -- the DCF/2 compresses 5 elements for
                every 1 that it stores.  Data inloads about 20% faster at this
                setting than at full compression (100).  Setting this value to
                0 turns off foreground compression and improves disk access
                speeds, but it provides the least space recovery.  (Setting
                this value to 0 during run-time is recommended only after your
                initial inload to the VDU, when most of the data in the VDU is
                compressed.  Disk access speeds will be fastest and new data
                can be compressed later using DCF2PAKR.)  Setting this value to
                100 turns on full foreground compression and provides the
                greatest space recovery, but disk access speeds are slower.

 SET DCF2_ACP_COMPRESSION_LEVEL=2
    Sets the level to which data is compressed.

      Minimum = 1 [Earlier versions of the DCF/2; least compression]
      Maximum = 3 [Greatest compression]
                The default setting is 2.  The greater the compression level,
                the more work and longer it takes to do.  The lower the value
                of this setting, the less compressed the data will be.  The
                higher the value, the greater the compression.

 SET DCF2_PDD_WAIT=0
    Sets the period of time in milliseconds that the physical device driver
    waits before processing the next request packet for your virtual disks.

      Minimum = 0
      Maximum = 127
                The default setting is 0 milliseconds.  The physical device
                driver processes requests continuously.  This can "load" your
                system.  To decrease the impact of this loading on your other
                foreground processes, increase this value -- start by
                increasing it to 1 millisecond, then 5 milliseconds.  As the
                value increases, the performance of virtual disk based programs
                and processes will decline and the performance of non-virtual
                disk based programs or processes will improve.

 SET DCF2_ACP_PRIORITY=3
    The priority is the weight given by OS/2 to requests for processing time
    from a job.  Requests from jobs running at a higher process priority are
    serviced first.  There are four priority levels to choose from:  1=Idle
    Time, 2=Normal, 3=Time Critical and  4=Server  Note that level 3 (time
    critical) is actually a "higher" priority than server (level 4).

      Minimum = 1 [Idle Time -- not recommended]
      Maximum = 3 [Time Critical]
                The default setting is 3.  The DCF/2's performance is best
                (fastest) with the default setting.  By setting this value to 2
                or 4, you can reduce the impact of the DCF/2 on other
                processing running in the foreground or system loading. It will
                slow the DCF/2's performance.  Do not set the priority to 1 --
                OS/2 will process any and every other request first!

 SET DCF2_ACP_PRIORITY_DELTA=31
    The delta is the thread priority within the process priority.

      Minimum = 0
      Maximum = 31
                The default setting is 31.

 SET DCF2_ACP_AUTO_OPTIMIZE_MINS=60
    Sets the number of minutes of disk idle time that must elapse before
    auto-optimize is scheduled to begin on a virtual disk having more than
    DCF2_ACP_AUTO_OPTIMIZE_KB_FREE kilobytes of extents and free space in use.

      Minimum = 0 [disables the auto-optimize feature]
      Maximum = 50,000 [35 days]
                The default setting is 60 minutes.  If the amount of space in
                use on the virtual disk by extents and free space is greater
                than the threshold amount and no write requests are received by
                any of your virtual disks for the countdown time, the
                auto-optimize is scheduled.  When an auto-optimize of the VDU
                is interrupted, the idle time countdown timer is reset to the
                value indicated by this variable.

 SET DCF2_ACP_AUTO_OPTIMIZE_LEVEL=0
    Sets the level of optimization.  The optimize level has a direct impact on
    the amount of time required to complete disk optimization and the amount of
    physical space recovered.  Levels are 0 through 4.

      Minimum = 0 [Quick Shuffle]
      Maximum = 1 [Purge, recompress and pack]
                The default setting is 0, which quickly "shuffles" free space
                out of the virtual disk file.  1=Full Optimize -- purge deleted
                space, recompress and pack data; 2=Recompress, no purge;
                3=Purge, no recompress; 4=Compress stored, no purge, no
                recompress. The default setting is overridden if you launch the
                optimize from an OS/2 command line and specify an optimize
                level other than the default.  If auto-optimize is disabled,
                this setting is ignored.

 SET DCF2_ACP_AUTO_OPTIMIZE_KB_FREE=1024
    Sets the threshold number for kilobytes of space in use by extents and free
    space on the virtual disk.  Only when the amount of space in the virtual
    disk used by extents together with actual free space exceeds this threshold
    is the auto-optimize idle time countdown timer enabled.  Thus auto-optimise
    can only start if there is sufficient free space to warrant it AND the VDUs
    have been idle for the time set by DCF2_ACP_AUTO_OPTIMIZE_MINS as above.

      Minimum = 64 Kbytes
      Maximum = 8192 Kbytes
                The default setting is 1024 Kbytes (1 megabyte).  The smaller
                the threshold, the more frequently the auto-optimize idle time
                countdown timer is activated.  If the auto-optimize feature is
                disabled, this setting is ignored.

 SET DCF2_ACP_OUT_OF_SPACE_WARNING=3072
    Sets the threshold in kilobytes at which to display the red, "Out of Space
    Warning" message.

      Minimum = 512 Kbytes
      Maximum = 16384 Kbytes (16 megabytes)
                The default is 3072 Kbytes (3 megabytes) of space on the
                virtual disk's host drive.  When space available falls below
                the threshold, the DCF/2 warns you that you need to free up
                space on the VDU's host.  Do not ignore the "Out of Space"
                messages!

 SET DCF2_ACP_OUT_OF_SPACE_SUSPEND=512
    Sets the threshold in kilobytes at which to display "Out of Space All I/O
    to this VDU is Suspended" message.

      Minimum = 64 Kbytes
      Maximum = 5120 Kbytes (5 megabytes)
                The default setting is 512 Kbytes of space on the virtual
                disk's host drive.  When available space falls below this
                threshold all requests to write to the virtual disk are
                suspended until the amount of physical space on the host drive
                goes above the threshold.  As physical space approaches the
                threshold, the risk of finding yourself unable to access the
                data on your VDU due to insufficient space on the host goes up.
                Do not ignore the "Out of Space" messages!

 SET DCF2_ACP_MISSION_CRITICAL=1
    Disables HPFS caching and lazy writing on virtual disks.

      Minimum = 0 [caching enabled]
      Maximum = 1 [caching disabled]
                The default setting is 0 because we feel that the benefit of
                using the HPFS's sophisticated caching and lazy writing
                mechanisms far outweighs the risk of cached data being lost in
                the event that power to the computer system is lost. Enabling
                this variable will slow down performance on virtual disks only.
                It will not affect normal HPFS caching and lazy writes for
                non-virtual disks.

 SET DCF2_ACP_MAXAGE_SECS=5
    Sets the number of seconds of disk idle time before commiting cache blocks
    to disk and cleaning and closing the virtual disk container files.

      Minimum = 5
      Maximum = 60
                The default setting is 5 seconds.  The value for this setting
                must be equal or greater than the value for the HPFS's maxage.
                Note that the HPFS maxage is stated in milliseconds. The 5
                second default is the same as 5000 milliseconds.

 SET DCF2_ACP_NO_CLEAN_AND_CLOSE=0
    Disables the "Clean & Close" feature for all virtual disks.

      Minimum = 0 [Clean & Close enabled]
      Maximum = 1 [Clean & Close disabled]
                The default setting is 0.  The "Clean & Close" feature is
                enabled.  We do not recommend disabling the "Clean & Close"
                feature.

 SET DCF2_ACP_LOGNG=0
    Enables/disables logging of diagnostic messages to the the DCF2ACP.LOG file
    in the root of your boot drive.

      Minimum = 0 [logging disabled]
      Maximum = 1 [logging enabled]
                The default setting is 0.  This disables logging messages to
                the DCF2ACP. LOG file.  If you suspect a virtual disk problem,
                enable logging and debugging and restart your computer system.

 SET DCF2_ACP_DEBUG=0
    Enables/disables logging of diagnostic debug messages to the the
    DCF2ACP.LOG file in the root of your boot drive.

      Minimum = 0 [logging disabled]
      Maximum = 1 [logging enabled]
                The default setting is 0.  This disables logging of debug
                messages to the DCF2ACP. LOG file.  If you suspect a virtual
                disk problem, enable logging and debugging and restart your
                computer system.


ΓòÉΓòÉΓòÉ 11.1.4. Device Driver Priority ΓòÉΓòÉΓòÉ

                            New in DCF/2 Version 1.4!

The DCF/2 uses a physical device driver to create template block devices --
known to you as virtual disk units.  The physical device driver processes
requests from the virtual disk software controller, the DCF/2 ancillary control
process.  As installed, it does this on a continuous basis.

New in DCF/2 Version 1.4 is the ability to control the load this continuous
processing can have on your system.  When the appropriate device driver
environment variable is set to a value of 1 (millisecond) or more, it causes
the physical device driver to wait for that period of time before processing
the next request.  This allows other foreground processes additional processing
time and decreases foreground loading.

The device driver environment statement, default setting and accepted range are
as follows:

 SET DCF2_PDD_WAIT=0
    Sets the period of time in milliseconds that the physical device driver
    waits before processing the next request packet for your virtual disks.

      Minimum = 0
      Maximum = 127
                The default setting is 0 milliseconds.  To decrease loading on
                foreground processes, increase this value -- start by
                increasing it to 1 millisecond, then 5 milliseconds.  As the
                value increases, the performance of virtual disk based programs
                and processes will decline and the performance of non-virtual
                disk based programs or processes will improve.

 Two DCF/2 control process environment variables are used in conjunction with
 this variable.  These control process priority and the thread priority within
 the process priority.  These environment variables are:

 SET DCF2_ACP_PRIORITY=3
    The priority is the weight given by OS/2 to requests for processing time
    from the a job.  Requests from jobs running at a higher process priority
    are serviced first.  There are four priority levels to choose from:  1=Idle
    Time, 2=Normal, 3=Time Critical and  4=Server  Note that level 3 (time
    critical) is actually a "higher" priority than server (level 4).

      Minimum = 1 [Idle Time -- not recommended]
      Maximum = 3 [Time Critical]
                The default setting is 3.  This can have a significant slowing
                effect on jobs running in the foreground on your system.
                Setting this to either 2 or 4 will slow the DCF/2 down and
                reduce foreground loading.  Do NOT set the priority to 1 --
                OS/2 will process any and every other request first!

 SET DCF2_ACP_PRIORITY_DELTA=31
    The delta is the thread priority within the process priority.

      Minimum = 0
      Maximum = 31
                The default setting is 31.

 Related topics:

          Performance Tips


ΓòÉΓòÉΓòÉ 11.1.5. Optimize Utility ΓòÉΓòÉΓòÉ

The command syntax for DCF2PAKR:

                         DCF2PAKR /V:x [/O:n /P:i /p:j]

where "x" is the letter of the virtual disk to be optimized and optional
switches are enclosed in square brackets [ ].

The following table lists the optional parameters available for the DCF2PAKR
command and their default settings:

                  Optional Switches, Ranges & Default Settings

      ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
      ΓöéSwitch    ΓöéFunction            ΓöéAccepted Values     ΓöéDefault   Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/O:n      ΓöéRecover Space       Γöé0 through 4         Γöé/O:0      Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/P:i      ΓöéProcess Priority    Γöé1 through 4         Γöé2         Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/p:j      ΓöéProcess Delta       Γöé0 through 10        Γöé10        Γöé
      Γöé          ΓöéPriority            Γöé                    Γöé          Γöé
      ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ

 The following table lists the optional parameters which are used to set the
 optimize level.

                             Optimize Level Switches

      ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
      ΓöéValue     ΓöéFunction                                          Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/O:0      Γöé[Default] Quick Shuffle.  Shuffles free space out Γöé
      Γöé          Γöéof the virtual disk                               Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/O:1      ΓöéFull optimize:  Purge, recompress, & pack         Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/O:2      ΓöéNo purge.  Recompress & pack only                 Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/O:3      ΓöéPurge & pack.  No recompress                      Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/O:4      ΓöéPack only.  No purge or recompress                Γöé
      ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ

 The following table lists the optional parameters which are used to set the
 priority level for the optimize.

                             Priority Level Switches

      ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
      ΓöéSwitch    ΓöéFunction                                          Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/P:1      ΓöéIdle time.  The job is only serviced when your    Γöé
      Γöé          Γöésystem is completely idle.                        Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/P:2      Γöé[Default] Normal.  The job is serviced at regular Γöé
      Γöé          Γöéintervals.                                        Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/P:3      ΓöéTime Critical.  The job is serviced more often    Γöé
      Γöé          Γöéthan any other job.                               Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/P:4      ΓöéServer.  The job is serviced more often than thoseΓöé
      Γöé          Γöéat normal but less often than those at            Γöé
      Γöé          Γöétime-critical priority.                           Γöé
      ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ

 The following table lists the optional parameters which are used to set the
 thread priority within the priority level for the optimize.

                              Thread Level Switches

      ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
      ΓöéSwitch    ΓöéFunction                                          Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/p:0      ΓöéLow priority thread delta -- everything else      Γöé
      Γöé          Γöéhappens first!                                    Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/p:1...9  ΓöéPriority thread delta increases as the value      Γöé
      Γöé          Γöéincreases.                                        Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      Γöé/p:10     Γöé[Default] Middle high priority thread delta.      Γöé
      ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ


ΓòÉΓòÉΓòÉ 11.1.6. Monitor Program ΓòÉΓòÉΓòÉ

The DCF2MON.EXE program includes optional parameters that can either be used
from an OS/2 command line or set using the VDU LED icon's Settings Notebook on
your Desktop.  These are:

                       MONITOR.EXE Command Line Parameters

   Parameter           Function

   /U:x                "x" is the VDU drive letter for LED icon

   /x:n                "n" is a decimal that designates the x coordinate
                       location of the LED icon on your Desktop.

   /y:n                "n" is a decimal that designates the y coordinate
                       location of the LED icon on your Desktop.

   /t:seconds          Sets the number of seconds between LED icon refreshes.
                       Increase this if you feel the monitor refreshes are
                       loading your system.  (Applies to certain video
                       adaptors.)

   /w                  Adds the monitor processes to the Window List

   /b                  Sets LED display for monochrome monitor

 If you have difficulty getting OS/2 to remember the position of your LED
 Monitors, drag them to your preferred position, and then shut them down by
 double clicking on the LED icon.  Next time you restart OS/2 after a system
 shut down LEDs should be where you left them.


ΓòÉΓòÉΓòÉ 11.2. Startup with more than 5 Virtual Disks ΓòÉΓòÉΓòÉ

Some users have reported problems when starting up with more than five virtual
disks.  The workaround for this situation is to create a command procedure that
stops the DCF/2 control processes and uses the SET command to point to the path
for each VDU and finally restarts the DCF/2 control processes.  The command
procedure is run after your desktop is up.

In the following example, we create a file will call STARTALL.CMD.  This
command is only executed after all virtual disk activity (as indicated by the
monitor LEDs) has completed.  (If included in your STARTUP folder, it should
include a pause of a sufficient number of seconds to allow for this disk
activity to complete before issuing the command to stop the control processes.)

The command has three parts:

       1. The first line is the command to stop the DCF/2 control processes.

       2. The next ten lines contain a SET statement for each of the 10 virtual
          disks to be started.

       3. The last line is the command to start the DCF/2 control processes.

 The command is run only after all the monitor LEDs stop flashing following
 your system startup.  The text of the command looks like the following:

          dcf2 /-
          SET DCF2_VDU_D=C:\dcf2\dcf2_D.vdu
          SET DCF2_VDU_E=C:\realvdus\dcf2_E.vdu
          SET DCF2_VDU_F=C:\dcf2\dcf2_F.vdu
          SET DCF2_VDU_G=C:\dcf2\dcf2_G.vdu
          SET DCF2_VDU_h=C:\realvdus\dcf2_h.vdu
          SET DCF2_VDU_i=C:\dcf2\sampler1.vdu
          SET DCF2_VDU_j=C:\dcf2\sampler2.vdu
          SET DCF2_VDU_k=C:\dcf2\sampler3.vdu
          SET DCF2_VDU_l=C:\dcf2\sampler4.vdu
          SET DCF2_VDU_m=C:\dcf2\sampler5.vdu
          dcf2 /+ /T:5 /m /t:5 /s
          exit

 In the above example case, the virtual disks D: through H: have identical SET
 statements in the CONFIG.SYS file.  Virtual disks I: through M: do not -- or,
 if they do, the statements are preceded by the REM comment.  What the command
 does is to effectively mount all of the virtual disks at one time.

 Once you have created a similar file, you may also want to create a desktop
 object for it.  If you do not know how to create a desktop object, refer to
 OS/2's online help.


ΓòÉΓòÉΓòÉ 11.3. Tip & Techniques ΓòÉΓòÉΓòÉ

The following Tips & Techniques for using the DCF/2 were contributed by people
who use the DCF/2.

       o  Updating the HPFS.IFS on Your OS/2 Disk 1
       o  Maintenance Partition, Dual Boot, etc.
       o  Loading Devices from the CONFIG.SYS
       o  Using the DCF/2 on Laptops
       o  Using the DCF/2 on Read/Write or Magneto Optical Drives
       o  Using an Alternative Startup
       o  Using the DCF/2 and Netware
       o  Hints for Applications
       o  Performance Tips


ΓòÉΓòÉΓòÉ 11.3.1. Updating the HPFS.IFS on Your OS/2 Disk 1 ΓòÉΓòÉΓòÉ

If you need to boot from the OS/2 install diskettes for a manual CHKDSK of the
physical drives, copy the HPFS.IFS from the DCF/2 distribution disk to your
OS/2 disk 1 before running CHKDSK.  You MUST run CHKDSK from diskette using the
same HPFS.IFS as you are running on your system.  Remember, that during the
DCF/2 installation, the install program may have updated your HPFS.IFS.  If the
date and time stamp of this file is later than that of the HPFS.IFS on your
OS/2 disk 1, replace the HPFS.IFS on your Disk 1.  The date and time of the
file rather than the size is the key.


ΓòÉΓòÉΓòÉ 11.3.2. Maintenance Partition, Dual Boot, etc. ΓòÉΓòÉΓòÉ

Creating a Maintenance Partition

While you may never need one, should "disaster strike", you will not regret the
time you spent creating a small -- 3MB, for example -- maintenance partition.

Include on your maintenance partition a small editor (in case you should need
need one to edit your CONFIG.SYS.)  Also include CHKDSK.COM, UHPFS.DLL and
HPFS.IFS (make sure these are the versions currently in use on your system), so
that if you need to run CHKDSK on your physical drive, your can do so without
having to locate your OS/2 disks.

Creating a Dual Boot Command

If you use OS/2's dual boot feature, you want to make sure that you always shut
down the DCF/2 before booting DOS.  The best way to do this is by creating a
simple command procedure.

Use an editor -- EPM comes with OS/2 -- to create a simple text file that runs
the DCF2 shut down and then executes the OS/2 boot command.  The text file
looks like the following:  (In the example, the boot drive is C:, and the DCF2
program directory is on C:  Change these references as appropriate for your
system.)

                    C:
                    CD \dcf2
                    DCF2 /-
                    \OS2\BOOT /DOS
                    exit

 Save the file as, for example, DUALDCF2.CMD.  Then, create a Desktop object
 that when selected will launch the command procedure whenever you want to dual
 boot.  If you are unfamiliar with creating desktop objects, please refer to
 OS/2's online help.


ΓòÉΓòÉΓòÉ 11.3.3. Loading Devices from the CONFIG.SYS ΓòÉΓòÉΓòÉ

Device drivers which are loaded during the processing of the CONFIG.SYS prior
to the DCF2PDD.SYS, should not be stored on a VDU.

This version of the DCF/2 includes an OPTIONAL early startup using the
DCF2MGR.SYS. The DCF2MGR.SYS executes the DCF/2 control program during system
initialization instead of at the completion of it.  The earlier startup makes
your virtual disks available in time OS/2 to load an application's device
driver from virtual rather than physical storage.  If you choose to load these
device drivers from a virtual disk, make sure that their DEVICE= statement in
your CONFIG.SYS file comes AFTER the DCF/2's.

If you try the early startup and your system traps, you will need to revert to
starting the DCF/2 after OS/2 system initialization is completed.  This means
using the CALL=x:\DCF2\DCF2.EXE /a:startup statement at the end of your
CONFIG.SYS file.

In this case, device drivers for applications stored on your virtual disks will
need to load from a physical directory or subdirectory identical to the
program's VDU-based directory or subdirectory.


ΓòÉΓòÉΓòÉ 11.3.4. Using the DCF/2 on Laptops ΓòÉΓòÉΓòÉ

A laptop computer often has drive letters available when portable that are not
available when the computer is used with a docking station.  So that virtual
disks retain their drive letter assignments both when the system is portable
and when it is docked, we create additional, "dummy" virtual disk units.

The easiest approach is to begin with a simple table like the following one,
which lists each drive letter and whether it is in use or available when the
computer is undocked or docked:

                                        ΓöîΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
                                        Γöé   ΓöéUndocked    ΓöéDocked      Γöé
                                        Γö£ΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
                                        ΓöéC: Γöéin use      Γöéin use      Γöé
                                        Γö£ΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
                                        ΓöéD: Γöéin use      Γöéin use      Γöé
                                        Γö£ΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
                                        ΓöéE: Γöéavailable   Γöéin use      Γöé
                                        Γö£ΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
                                        ΓöéF: Γöéavailable   Γöéin use      Γöé
                                        Γö£ΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
                                        ΓöéG: Γöéavailable   Γöéin use      Γöé
                                        Γö£ΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
                                        ΓöéH: Γöéavailable   Γöéavailable   Γöé
                                        Γö£ΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
                                        ΓöéI: Γöéavailable   Γöéavailable   Γöé
                                        ΓööΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ

 For the following example, we will refer to this table.  The steps are:

       1. Identify the first drive letter that is available both when undocked
          and docked.  (In the above example, this is H:)
       2. Count the number of drive letters available undocked before the first
          available drive letter docked.  (In the above example, this is 3.)
       3. Decide how many "real" virtual disks you want for use.  (For our
          example, we'll say 2.)
       4. Determine the total number of VDUs to create using the DCF/2
          installation program by adding items #2 and #3.  (In our example, we
          add 3+2 = 5 Total VDUs).

 In the example, virtual disk H: and I: are our "real" virtual disks.  We run
 the DCF/2 installation program.  During the part of the installation that
 creates the virtual disks for each drive letter, we confirm that we want to
 create the virtual disk only for our "real" drive letters, H: and I:.

       1. When prompted to enter the total number of VDUs to create, enter 5.
       2. If installing the DCF/2 while the computer is undocked:  When
          prompted to confirm the creation of virtual disk letters before H:,
          answer NO.
       3. When prompted to confirm the creation of virtual disk letter H:,
          answer YES.
       4. When prompted to confirm the creation virtual disk letter I:, answer
          YES.
       5. If installing the DCF/2 while the computer is docked:  When prompted
          to confirm the creation of virtual disk letters after I:, answer NO.

 At the end of the installation program, you have the opportunity to edit the
 order of statements written by the program to your CONFIG.SYS file.  Had we
 installed the DCF/2 when undocked and, during VDU creation, answered YES for
 each of the 5 VDUs, the statements in the CONFIG.SYS file would look like
 this:

          DEVICE=C:\DCF2\DCF2PDD.SYS /U:5
          DEVICE=C:\DCF2\DCF2CDE.SYS
          DEVICE=C:\DCF2\DCF2MGR.SYS
          SET DCF2_VDU_E=C:\DCF2\DCF2_E.VDU
          SET DCF2_VDU_F=C:\DCF2\DCF2_F.VDU
          SET DCF2_VDU_G=D:\DCF2\DCF2_G.VDU
          SET DCF2_VDU_H=C:\DCF2\DCF2_H.VDU
          SET DCF2_VDU_I=D:\DCF2\DCF2_I.VDU

 Because we only answered YES to confirm the creation of H: and I:, the
 statements written to the CONFIG.SYS file look like this:

          DEVICE=C:\DCF2\DCF2PDD.SYS /U:5
          DEVICE=C:\DCF2\DCF2CDE.SYS
          DEVICE=C:\DCF2\DCF2MGR.SYS
          SET DCF2_VDU_H=C:\DCF2\DCF2_H.VDU
          SET DCF2_VDU_I=D:\DCF2\DCF2_I.VDU

 As a result, regardless of whether the system is undocked or docked, the
 virtual disks always come up as drives H: and I:

 For OS/2 WARP 3.0 users,if you need to set up different VDUs when docked and
 undocked, you may wish to use different CONFIG.SYS files via the "Recovery
 Choices" Screen. See your OS/2 WARP User's Guide for details (beginning on p.
 215 in the U.S. Edition).


ΓòÉΓòÉΓòÉ 11.3.5. Using the DCF/2 on Read/Write or Magneto Optical Drives ΓòÉΓòÉΓòÉ

In the event of an improper shut down (loss of power, trap, hang, etc.) for the
case in which the VDU host is a Read/Write or Magneto Optical, do the
following:

       1. Take the media out of the drive on startup.
       2. Let the DCF/2 AutoCheck run.
       3. From an OS/2 Command Processor, change to the DCF2 program directory
          and shutdown the DCF2ACP.  Use the command, DCF2 /- or DCF2
          /A:SHUTDOWN.
       4. Put the media in the drive and do CHKDSK /F on the physical media.
       5. From an OS/2 Command Processor, change to the DCF2 program directory
          and startup the DCF2ACP.  Use the command, DCF2 /+ or DCF2
          /A:STARTUP.
       6. Let the DCF/2 AutoCheck run.


ΓòÉΓòÉΓòÉ 11.3.6. Using an Alternative Startup ΓòÉΓòÉΓòÉ

Use RESTART=EVERYTHING in your CONFIG.SYS.  If you don't want everything
restarted for some reason, use CTRL+SHIFT+F1 as soon as the desktop first
appears to stop everything (including the DCF/2) from restarting.  (You can let
go of the keys when all icons appear.)  This also suppresses the objects in the
startup folder from starting.

Create a .CMD file, which contains the DCF2 /A:Startup command.  Place a
program object pointing to the .CMD in your STARTUP folder.


ΓòÉΓòÉΓòÉ 11.3.7. Using the DCF/2 and Netware ΓòÉΓòÉΓòÉ

If your VDU host is a Netware file server volume, the following tips should be
helpful.

       1. Run your Netware login from the CONFIG.SYS using
          "CALL=x:\Netware\login.exe". Place this CALL statement AFTER the
          block of Netware statements and BEFORE the "CALL=x:\DCF2\DCF2.EXE
          /A:STARTUP."

       2. Shutdown the DCF/2 BEFORE logging out.  The login-logout process can
          be automated using a REXX command procedure like the one that
          follows.

       3. Network-based VDUs are not shareable by two or more workstations at
          the same time. They can be accessed serially.

       4. A Netware-based VDU is a good place to keep personal data, but not
          recommended for storing Netware login, logout and other utilities.

 Sample REXX Command to Synchronize Login and Logout

          /* Netware login / logout */
          PARSE UPPER SOURCE . . progName
          progName = FileSpec('Name',progName)
          PARSE ARG args
          /* Shutdown DCF/2 in preparation for logout */
          'd:\dcf2\dcf2.exe /a:shutdown'
          SELECT
          WHEN progName = 'LOGIN.CMD' THEN
             'd:\netware\login.exe args
          WHEN progName = 'LOGOUT.CMD' THEN
             'd:\netware\logout.exe'
          OTHERWISE
             SAY 'Program name must be LOGIN.CMD or LOGOUT.CMD'
          END
          /* Startup DCF/2 now that drives have been remapped */
          'd:\dcf2\dcf2 /a:startup'
          EXIT

 For initial startup, use the CALL statement in the CONFIG.SYS.  Then use the
 above sample program or one like it for subsequent logins and logouts.  You
 can make two copies of the sample program -- name one LOGIN.CMD and the other
 LOGOUT.CMD. You may need to copy the login.exe and logout.exe programs to a
 local drive.


ΓòÉΓòÉΓòÉ 11.3.8. Hints for Applications ΓòÉΓòÉΓòÉ

Each application you run has a personality and quirks all its own.  We have
tested a wide variety of DOS, Windows and OS/2 applications.  For most of them,
the transition from physical to virtual is effortless.  They run from a virtual
drive just as they did from a physical one.

The following is a collection of hints contributed by DCF/2 users, based on
their experiences with some of the more finicky applications.

DeScribe 5.0, the OS/2 Toolkit and CSet++

DeScribe 5.0, the OS/2 Toolkit and CSet++ are among a group of applications
which first copy compressed installation files to your disk, uncompress the
files and then delete the files used for the installation.  The copying,
uncompressing and deleting of files to a virtual disk using compression means
lots of added "work" for the DCF/2.

Installations of programs like these will at best proceed slowly and at worst
will hang.  The program will also take up about TWICE the space the program's
installation says it requires.  Be sure you have sufficient space before you
begin to install it.

The workaround, when installing programs like these, is either to first install
the application to a physical or network disk and then move it to a virtual
disk; or, to disable compression on the virtual disk prior to starting the
installation using the following environment variable found in your CONFIG.SYS:

          SET DCF2_ACP_FOREGROUND_COMPRESS_RATE=0

 In this way, you bypass compressing then decompressing and recompressing the
 files -- all of which requires a good deal of energy for no real purpose.
 Then, at your convenience, use the optimize utility from a command line with
 the /O:1 parameter to purge the space freed up when the installation program
 deleted the files it used for the installation, and then recompress and pack
 all the files on the virtual disk.

 Windows Programs

 Your Windows programs can be run from virtual disks just as well as from
 physical and logical disks.

 When installing Windows programs to a virtual disk, it is helpful to keep in
 mind that even though you are installing the program to the virtual disk, the
 program is more likely than not also installing certain files to the Windows
 subdirectory (or subdirectories) on your physical disk.

 When you start a Windows application, part of it's startup includes doing what
 is known as a "reset media" on each and every device on your system.  (Watch
 the DCF/2 LED monitors flicker when you start a Windows application --
 regardless of whether it is stored on a virtual disk or not.)

 When a Windows application attempts to do a "reset media" on a virtual disk
 that is being optimized, we pop up a message.  You can either interrupt the
 optimize and let the Windows application continue to load, or you can allow
 the optimize to complete -- knowing that the Windows application will not load
 until it can do it's reset media on the virtual drive -- when the optimization
 is complete.

 To avoid this ticklish situation, just calls for a bit of advance planning. If
 you know you want to run a Windows application and will be optimizing virtual
 disks at the same time, start the Windows application first, then the
 optimize.

 AmiPro 3.0a & AmiPro 3.0b

 AmiPro style sheets seem to want to load from a physical disk.  Not allowing
 them to do so can result in a SYS3175 error.  Workaround:  Move all of AmiPro
 to the VDU, but make sure that the style sheet directory is on a physical
 disk.  Then modify AMIUSER3.INI (use AmiPro's INIEDIT.EXE), so that the INI
 entry for the style sheet directory points to the right place.

 Refer to the VIEW file in your DCF2 program directory called AMIFIX.INF for
 complete details.

 FaxWorks

 On systems not starting the DCF/2 from the DCF2MGR.SYS in the CONFIG.SYS, OS/2
 may try to load the FaxWorks device driver before the DCF/2 starts up.  As a
 result, if it is on a VDU, the device is not found.  Workaround:  Either start
 the DCF/2 from the DCF2MGR.SYS and make sure that the FaxWorks device driver
 appears after the DCF/2 DEVICE= statements in your CONFIG.SYS; or, load
 FaxWorks FMD.SYS from an identical FaxWorks directory on a physical drive.

 Communications Manager/2

 If Communications Manager/2 (and any number of other programs which add
 statements to your CONFIG.SYS) is installed after the DCF/2, edit your
 CONFIG.SYS so that the last statement in the file is the CALL=x:\DCF2\DCF2.EXE
 /A:STARTUP.

 In the case of Communications Manager/2, this will preclude its startup
 process from interferring with that of your VDUs.


ΓòÉΓòÉΓòÉ 11.3.9. Performance Tips ΓòÉΓòÉΓòÉ

The DCF/2 is shipped tuned for the best (faster) performance with the following
default settings:

      ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
      ΓöéParameter                               ΓöéDefault   ΓöéLeast LoadΓöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      ΓöéSET DCF2_ACP_PRIORITY=                  Γöé3         Γöé2         Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      ΓöéSET DCF2_ACP_PRIORITY_DELTA=            Γöé31        Γöé0         Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      ΓöéSET DCF2_ACP_FOREGROUND_COMPRESS_RATE=  Γöé5         Γöé100*      Γöé
      Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
      ΓöéSET DCF2_PDD_WAIT=                      Γöé0         Γöé127       Γöé
      ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ

 Note:  The foreground compress rate allows you to effectively turn compression
        OFF (when set to 0) or ON (when set between 1 and 100).  The values
        between 1 and 100 determine how many "elements" of data are compressed
        in the foreground before the next one is stored uncompressed for
        compression later.  The lower the number, the better (faster) the
        performance.

 If you feel the DCF/2 at the default settings causes an unacceptable level of
 system loading, you can make the following adjustments (in the order in which
 they are listed) to the DCF/2 statements in your CONFIG.SYS file:

       1. On the line reading "SET DCF2_PDD_WAIT= 0", change the 0 to 1 or 5 or
          more (up to a maximum of 127).

       2. On the line reading "SET DCF2_ACP_PRIORITY_DELTA=31", reduce the
          value from 31 to something greater than 0.

       3. On the line reading "SET DCF2_ACP_PRIORITY=3", change the priority to
          4 (server) or 2 (normal).

       4. Save the changes and reboot to initialize them.

 You may want to wait to make any changes to the default settings until after a
 major inload to your virtual disks is complete.  Tests show that during an
 XCOPY into a VDU, setting the priority to 3 (time critical) and delta to 31
 cut the inload time in half!

 Other suggestions for optimal DCF/2 performance are:

       1. During inload -- if you have limited disk space available -- SET the
          following environment variables in your CONFIG.SYS file:

            a. SET DCF2_ACP_FOREGROUND_COMPRESS_RATE=100
            b. SET DCF2_ACP_COMPRESSION_LEVEL=3

       2. During inload -- if you have plenty of disk space available -- SET
          the following environment variable in your CONFIG.SYS file:

            a. SET DCF2_ACP_FOREGROUND_COMPRESS_RATE=0

       3. During normal operation -- if you have disk space available -- SET
          the following environment variable in your CONFIG.SYS file:

            a. SET DCF2_ACP_FOREGROUND_COMPRESS_RATE=0

       4. During normal operation -- if you have limited disk space available
          -- SET the following environment variables in your CONFIG.SYS file:

            a. SET DCF2_ACP_FOREGROUND_COMPRESS_RATE=1 [or 2 or 3]
            b. SET DCF2_ACP_COMPRESSION_LEVEL=1

 Related topic:

          Environment Variables


ΓòÉΓòÉΓòÉ 11.4. Cache Considerations ΓòÉΓòÉΓòÉ

Select from the tables below based upon whether your system is HPFS-only,
FAT-only, Both with HPFS Active and FAT Passive or Both with HPFS Passive and
FAT Active. For our purposes, "active" and "passive" are descriptors for the
way a partition is used.  If it is seldom used, consider it "passive."  If a
lot of disk intensive I/O occurs on the partition, consider it "active."

 When the DCF/2 is in use on a system, it follows that the HPFS is also
installed.


Case1 : HPFSPartitionsOnly

ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
ΓöéRAM   ΓöéCACHE ΓöéLAZY      ΓöéMAXAGE  ΓöéDISKIDLE  ΓöéBUFFERIDLEΓöéOther               Γöé
Γöé      Γöé      ΓöéWRITES    Γöé        Γöé          Γöé          Γöé                    Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
Γöé16MB  Γöé2048  Γöé/LAZY:on  Γöé40000   Γöé30000     Γöé20000     ΓöéREM out DISKCACHE   Γöé
Γöé      Γöé      Γöé          Γöé        Γöé          Γöé          Γöéstatement           Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
Γöé12MB  Γöé1536  ΓöéSame      ΓöéSame    ΓöéSame      ΓöéSame      ΓöéSame                Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
Γöé8MB   Γöé1024  ΓöéSame      ΓöéSame    ΓöéSame      ΓöéSame      ΓöéSame                Γöé
ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ


Case 2:  FAT Partitions Only

ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
ΓöéRAM   ΓöéCACHE ΓöéLAZY      ΓöéOther                                           Γöé
Γöé      Γöé      ΓöéWRITES    Γöé                                                Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
Γöé16MB  Γöé2048  Γöé/LW       ΓöéREM out the HPFS.IFS statement                  Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
Γöé12MB  Γöé1536  ΓöéSame      ΓöéSame                                            Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
Γöé8MB   Γöé1024  ΓöéSame      ΓöéSame                                            Γöé
ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ


Case 3:  HPFS and FAT with HPFS Active

ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
ΓöéRAM   ΓöéCACHE ΓöéLAZY      ΓöéMAXAGE  ΓöéDISKIDLE  ΓöéBUFFERIDLEΓöéDISKCACHE           Γöé
Γöé      Γöé      ΓöéWRITES    Γöé        Γöé          Γöé          Γöé                    Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
Γöé16MB  Γöé2048  Γöé/LAZY:on  Γöé40000   Γöé30000     Γöé20000     Γöé512-1024            Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
Γöé12MB  Γöé1536  ΓöéSame      ΓöéSame    ΓöéSame      ΓöéSame      Γöé256-512             Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
Γöé8MB   Γöé1024  ΓöéSame      ΓöéSame    ΓöéSame      ΓöéSame      Γöé128-256             Γöé
ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ


Case 4:  HPFS and FAT with FAT Active

ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
ΓöéRAM   ΓöéCACHE ΓöéHPFS LAZY ΓöéMAXAGE  ΓöéDISKIDLE  ΓöéBUFFERIDLEΓöéDISKCACHE ΓöéFAT LAZY  Γöé
Γöé      Γöé      ΓöéWRITES    Γöé        Γöé          Γöé          Γöé          ΓöéWRITES    Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
Γöé16MB  Γöé1024  Γöé/LAZY:on  Γöé40000   Γöé30000     Γöé20000     Γöé2048      Γöé/LW       Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
Γöé12MB  Γöé768   ΓöéSame      ΓöéSame    ΓöéSame      ΓöéSame      Γöé1536      ΓöéSame      Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
Γöé8MB   Γöé512   ΓöéSame      ΓöéSame    ΓöéSame      ΓöéSame      Γöé1024      ΓöéSame      Γöé
ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ

Based upon the file system and cache tuning testing, the following are true:

       o  The HPFS actually requires 128 to 130K of committed memory -- as
          opposed to the widely perceived 512K.  As cache size increases to 2MB
          (2048), this requirement increases as well, up to a maximum of about
          240K.

       o  The optimal cache size seems to be 1536.

       o  When comparing the relative merits of the HPFS versus FAT, consider
          the following: On partitions of identical size, the HPFS gives you
          about 15% more space and performance is about 28% better!

       o  Instead of continuing to increase performance, a DISKCACHE value in
          excess of 2048 seems to degrade performance rather than improve it.


ΓòÉΓòÉΓòÉ 11.5. 20 Questions About DCF/2 ΓòÉΓòÉΓòÉ

1.) Can I compress HPFS partitions using the DCF/2?

Yes, but you need to be running OS/2 2.11 (OS/2 2.1 plus the Service Pak) or
higher to do so.

2.)  How does the DCF/2 differ from Stacker for OS/2 and DOS?

          The DCF/2 allows the user to compress files stored on either FAT- or
          HPFS-formatted partitions.

          The DCF/2 was designed for a multitasking operating system, OS/2 2.x
          -- not "ported" from a single tasking operating system, DOS.

          DCF/2 compressed drives can "reside" on any device supported by OS/2
          -- be they FAT- or HPFS-formatted, removable or network devices.

          Compressed drives grow dynamically [--] the user doesn't have to
          pre-allocate a big chunk of space for the compressed drive.

          Only the DCF/2 lets you try on-the-fly data compression without
          committing yourself or your entire system to the idea in advance.

 3.)  What does "on-the-fly" mean?

 On-the-fly compression products like the DCF/2 create a special file, which
 serves as a container for compressed data.  When an application request data
 stored in this way, the data is automatically compressed or decompressed
 "on-the-fly."  The user does not issue a command to "unzip" or "unpak" the
 files he wants uncompressed.

 4.)  What is a VDU?

 VDU stands for Virtual Disk Unit.  It is the term used to describe the
 architecture of the DCF/2's compressed drive. Like a physical disk unit,  it
 works with low level OS/2 utilities like FORMAT and CHKDSK. Like a logical
 disk unit (e.g., a network drive), it isn't something you can reach out and
 touch.

 5.)  I haven't installed OS/2 yet.  Which do I install first, OS/2 or the
 DCF/2?

 Install OS/2 first, then the DCF/2.

 6.)  I run dual boot.  Can I access the compressed drive when I boot native
 DOS?

 Use the DCF/2 only to compress files and data you don't need access to when
 you boot native DOS.  OS/2 must be running to access the compressed data.
 From DOS the VDU looks like a big file.  The DCF/2 does give the user a great
 deal of flexibility with regard to picking and choosing what to compress and
 what not to compress.

 7.)  Do I have to back everything off of my system and reformat my hard drive?

  No.  There is no need to back everything off of your drive or to reformat it
 before installing the DCF/2.

 8.)  Does the DCF/2 compress an entire drive automatically?

 No.  Once a VDU is created and formatted, it is empty until the user moves
 programs and data onto it using the tools and utilities he normally uses to
 moves files and directories on his system, i.e., xcopy and delete or the OS/2
 drives icon.  The VDU grows dynamically as data is moved onto it, and can be
 made smaller when data is eliminated from it.

 9.)  Can I compress OS/2?

 It is not recommended with version 1.4.  You can compress WINOS2, EPM (the
 Enhanced Editor) and OS/2 reference files (.INF).  However, if OS/2 needs to
 be reinstalled or the user plans to beta test a new version of the operating
 system, he or she should concentrate on moving program and data files to the
 VDU and leave OS/2 the full amount of space its installation requires.

 10.)  I am running OS/2 1.3.  Can I use the DCF/2?

 No.  The DCF/2 doesn't support OS/2 1.3.  The DCF/2 can support VDU container
 files on FAT partitions only with OS/2 2.1 and VDU container files on FAT or
 HPFS partitions with OS/2 2.11 (i.e. OS/2 2.1 plus the service pak) or higher.

 11.)  Can I compress floppies?

 Yes.

 12.)  Can I compress my magneto or read-write optical drive?

 Yes.

 13.)  Can I put VDUs on a network drive?

 Yes.

 14.)  Can I compress the OS/2 SWAPPER.DAT file?

 No, not with version 1.4.

 15.)  Does the DCF/2 "double" my drive?

 The compression ratio for a VDU will vary with the type and mix of data on the
 system.  Typical compression ratios range from 1.5 to 1 (pre-compressed files,
 e.g., games, zipfiles, etc.) to 5 to 1 (user files, e.g., Ami Pro, etc.).

 Shipped with the DCF/2 is the Disk Compression Analysis Tool or DCAT.  It is a
 simple utility program which allows the user to analyze the data on his or her
 system in terms of how much space could be recovered if it were stored on a
 compressed drive.

 16.)  Can I use the DCF/2 with OS/2 for Windows?

 Yes.

 17.)  Can I use the DCF/2 with the new OS/2 WARP Versions?

 Yes.

 18.)  Does the DCF/2 support drive letter swapping so that after I compress
 everything on my D: drive, I still have only a D: drive?

 No.  Drive letter swapping is not supported in version 1.4.  The VDU takes the
 next available physical drive letter on the users system. For example, if the
 user's system has a C:, D: and E:, the first VDU will be drive letter F: and
 so on.

 19.)  Why are the VDUs always formatted using the HPFS?

 Because the HPFS is a much faster and efficient way to manage the data store
 on a computer system.  In addition, it allows the user to use longer, more
 descriptive file names than the traditional "Eight-Dot-Three" naming
 convention.  "Statements" to the effect that the HPFS requires half a megabyte
 of memory are completely wrong. Even with the maximum cache size allowed
 (2MB), the HPFS never uses more than about 200 to 300 Kbytes of memory.

 20.) I am using DOS 6 with compression.  Does DCF/2 include a conversion
 utility?

 No.  The user has to "unstack" the compressed drive, install OS/2 (if not
 already installed), then install the DCF/2 and move the data to be compressed
 onto the VDU(s).


ΓòÉΓòÉΓòÉ 11.6. Trademarks, Copyrights and Acknowledgements ΓòÉΓòÉΓòÉ

Proportional Software Corportation (PSC) provides this publication "as is"
without warranty of any kind, either express or implied, including but not
limited to the implied warranties of merchantability or fitness for a
particular purpose.

This publication could contain technical inaccuracies or typpographical errors.
Changes are periodically made to the information herein and the changes will be
incorporated in new editions of the publication.  PSC may make improvements
and/or changes in the products and/or the programs described in this
publication at any time.

       o  Trademarks and Copyrights
       o  Acknowledgments


ΓòÉΓòÉΓòÉ 11.6.1. Trademarks and Copyrights ΓòÉΓòÉΓòÉ

DCF/2(tm) and Disk Compression Facility for OS/2(tm) are trademarks of
Proportional Software.

IBM(r) and OS/2(r) are registered trademarks and Presentation Manager(tm) is a
trademark of International Business Machines Corporation.  CompuServe(r) is a
registered trademark of CompuServe Incorporated.  Relish for OS/2 Presentation
Manager(tm) is a trademark of Sundial Systems Corporation.  Lotus (r), AmiPro
for OS/2(r), 1-2-3 for OS/2(r), and Freelance Graphics(r) are registered
trademarks of Lotus Development Corporation.  FaxWorks(tm) is a trademark of
SofNet, Inc.

All other referenced products are trademarks or registered trademarks of their
respective manufacturers.

OS/2 files are being provided on behalf of IBM for maintenance purposes only
and the rights and licenses to these files are governed by the terms and
conditions of the user's OS/2 product license.

Copyright March 1995.  Proportional Software Corporation, 1717 Linden Lake Rd.,
Ft. Collins, CO 80524.

ALL RIGHTS RESERVED.


ΓòÉΓòÉΓòÉ 11.6.2. Acknowledgments ΓòÉΓòÉΓòÉ

The DCF/2 has been a complex and challenging undertaking.  Without the patience
of our customers and the complete support of Lee Reiswig's OS/2 Team, the
product would not exist today.

Proportional Software gratefully thanks and acknowledges the contributions of
the following individuals in particular:

          For invaluable technical assistance:  The entire IBM OS/2 ISV
          Technical Support Group, and in particular -- Mr. Orlando Portella
          and Charles Buck II. In addition to the IBM OS/2 Technical Support
          Group, we express our appreciation to Mr. Colin Powell, Mr. Felix
          Miro, Mr. Sam Detweiler, Mr. James Taylor and Mr. Jack Boyce.

          For his technical assistance, Mr. Wayne Kovsky of COLORAD/OS2, and
          for their review of and comments on the documentation, Guy Scharf and
          Christy Scharf.

          For the wealth of information their books have provided:  Mr. Mark
          Nelson, Mr. Raymond Westwater, Mr. Robert Lai, Dr. Mike Kogan : Dr.
          Harvey Dietel, Mr. Gilbert Held, Mr. Lawrence Kenah, Ms. Ruth
          Goldenberg, and Mr. Simon Bate.

          For their patience, moral support and encouragement:  Ms. Robin
          Frank, Mr. Toby Pennycuff, Mr. Tim Heacox and Mr. David Jackson.

          For making it all worthwhile:  our daugher Jennifer and son "Boo."