CD ROM Paradise Collection 4/CD ROM Paradise Collection 4 1995 Nov.iso/os2/dcf211b.zip/DCF2.HLP

OS/2 Help File | 1994-05-06 | 85KB | 1,904 lines

ΓòÉΓòÉΓòÉ 1. Table of Contents ΓòÉΓòÉΓòÉ

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

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


ΓòÉΓòÉΓòÉ 2. Introduction ΓòÉΓòÉΓòÉ

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

Unlike DOS compression products, which require you to have 50 MB of space free
in order to create a 100 MB compressed drive -- the compressed drives you
create using the DCF/2 grow dynamically.  With the DCF/2, when you create a
100MB compressed drive and format it, it occupies less than 350K of physical
space.  You can create your first "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 "VDU", 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 hard drive.

Unlike DOS compression products, DCF/2 compressed drives can reside on any
device supported under OS/2 -- network and removeable media (read-write
opticals, 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

If you have not yet updated your system to OS/2 2.11  (OS/2 2.1 plus the
Service Pak), you must do so in order to use the DCF/2 on your HPFS-formatted
drives.  If for some reason you cannot install OS/2 2.11 on your system, DCF/2
compressed drives must be placed only on non-HPFS "host" drives. The DCF/2 does
not support versions of OS/2 prior to OS/2 2.0.  To order the Service Pak, call
IBM at [phone].

If you are running OS/2 2.11 and the High Performance File System is installed,
but 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.

If you are running OS/2 2.11 and the High Performance File System is not
currently installed on your system, the DCF/2 install program will install the
OS/2 2.1 UHPFS.DLL and the HPFS.IFS dated the April 19, 1994, to the correct
directory and will add the HPFS statement to your CONFIG.SYS.

If you are running a version of OS/2 after 1.3 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.

Finally, if you are running a version of OS/2 after 1.3 but prior to 2.11, have
the High Performance File System installed and have partitions formatted as
HPFS, the DCF/2 installation program will update your HPFS.IFS to the OS/2 2.1
GA version. IN THIS CASE, DO NOT CREATE DCF/2 VIRTUAL DISK UNITS ON YOUR HPFS
FORMATTED PARTITIONS -- USE ONLY FAT-BASED HOSTS.

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.  Before you do so, however, you need to have a
basic understanding of the terms we use to describe the differences between the
three types of storage units [--] 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.

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.

Virtual Disk Unit

A DCF/2 Virtual Disk Unit (VDU) looks like a real, physical disk unit to OS/2.
It has real geometry (so many heads, so many sectors per track). You run low
level utilities like FORMAT and CHKDSK on it.  It does not exist in the
physical sense.  It "exists" as a "storage container" for your compressed data
on either a physical or a logical disk unit.


ΓòÉΓòÉΓòÉ 3. 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.

Note:  The DCF/2 Version 1.1b installation program should only be used to
       install the DCF/2 programs and create your first VDUs.  It is not
       intended to be used to create additional VDUs or to update VDUs created
       under previous versions of the DCF/2.

 If you currently have VDUs installed that were created using a previous
 version of the DCF/2, please refer to the appendix for converting old VDUs to
 Version 1.1b.

 Note:  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.  Drive letter swapping
        is not available in this release, but will be included in a future
        version of the software.  If you have network drives defined, please
        logoff of the network prior to running the DCF/2 install program.

 The section on installation covers the following topics:

     o Choosing the Target Drive
     o Selecting the Number of VDUs
     o Creating VDUs
     o Updating the Configuration
     o Restarting Your System
     o Formatting VDUs with AutoFormat
     o AutoChecking VDUs
     o Formatted, Clean and Ready for Data
     o DCF/2 OS/2 System Shutdown Program
     o Installing from a Network Server
     o Updating Workstation from a Server
     o Registration & Unlicensed Copies


ΓòÉΓòÉΓòÉ 3.1. Choosing the Target Drive ΓòÉΓòÉΓòÉ

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


ΓòÉΓòÉΓòÉ 3.2. 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.  This number can be changed at a later  time.

Note:  In choosing the number of VDUs to create (and realizing that almost no
       two systems are identical), take the following into consideration.  The
       data on a system usually falls into one of three categories and occupies
       more or less a fixed percentage of this physical space:


  Data Categorized by Frequency of Use

  ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
  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             Γöé
  Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
  ΓöéWrite often/Read often   Γöé15%                 ΓöéLive data                Γöé
  ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ

 Typically, applications and games compress at 1.5 - 1.75:1, user files
 compress at 1.75 - 2.25:1 and icons and communications threads compress at
 2.25 - 5.0:1.

 For a number of reasons, we recommend that you create several smaller VDUs
 rather than a few large ones.  We base this recommendation on the length of
 time required to run CHKDSK /F on a large VDU versus a smaller one; as well as
 the amount of time required to optimize a large VDU versus a smaller one.
 Finally multiple smaller VDUs offer greater backup flexibility.


ΓòÉΓòÉΓòÉ 3.3. Creating VDUs ΓòÉΓòÉΓòÉ

The first VDU you create will take the first physical 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. 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 will probably need to use
       one CONFIG.SYS when docked and a second CONFIG.SYS when running
       portable.  In the latter case, inserting VDISK statements for each of
       the physical devices not present when portable will allow the VDU drive
       letter to remain the same in both modes.

 Choosing Where to Put VDUs

 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.

 Selecting the Host Physical Unit

 The  "Host Physical Unit" is the physical location on which the Virtual Disk
 Unit resides.

 Note:  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.

 Selecting VDU Size

 The "Total Size" is the total capacity OS/2 will believe the DCF/2 Virtual
 Disk Unit to have.  You enter the size in MegaBytes rather than in bytes.

 Cancelling Selections

 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 for each subsequent VDU up to the total number of VDUs you requested.


ΓòÉΓòÉΓòÉ 3.4. 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.  The following is an example:

Example of Changes to the CONFIG.SYS File

"The ordering of the statements in your CONFIG.SYS file has been adjusted to
put the HPFS.IFS statement at the top, followed by the DISKCACHE statement if
you have FAT drives.  This is followed by your 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 DCF/2
CALL=x:\DCF2\DCF2.EXE /A:STARTUP statement.

Your HPFS and (optionally) your DISKCACHE statement may have been modified to
optimize your cache allocation and/or to add AUTOCHECK switches.

The DCF/2 requires that the HPFS.IFS have a minimum 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
any 'dirty' HPFS disks:

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

 The DISKCACHE statement is required only if you have FAT drives on your
 system.  If you have 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, and the AC:
 specifies which FAT drives to CHKDSK during system startup.  For additional
 information on the DISKCACHE statement, refer to the OS/2 Online Help.

     DISKCACHE=1024,LW,32,AC:C

 The following commands can improve your caching performance, depending on how
 you use your system:

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

 Due to the multithreaded nature of the OS/2 system startup, you may find that
 you need to place the above RUN commands in your STARTUP.CMD folder instead of
 in your CONFIG.SYS.

 The contents of your CONFIG.SYS file follow these statements and these are
 followed by the DCF/2 device, set and call statements at the end of your
 CONFIG.SYS.  The DCF/2 statements will be 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.  The /U:n defines n number of
 DCF/2 virtual disk units to be created.

     DEVICE=C:\DCF2\DCF2PDD.SYS /u:3
     DEVICE=C:\DCF2\DCF2CDE.SYS

 The DCF _VDU_x environment variable points to DCF/2 VDU x:

     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_VCP_LOGNG=3
      REM >> SET DCF2_ACP_DEBUG=3
      REM >> SET DCF2_VCP_DEBUG=3

 The following "CALL=" statement starts the DCF/2.  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 your STARTUP.CMD or to the command procedure
 that starts your network.

 The following call statement tells OS/2 to startup the DCF/2:

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

 You may delete the REM'd statements and delimiting lines if you prefer.  Do,
 however, exercise caution so as not to delete more than the comments."

 DCF/2 OS/2 System Shutdown Icon

 During the final part of the installation process, the program will place the
 DCF/2 icon 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.11b

 The README.11b file shipped on the DCF/2 disk contains the latest release
 notes for this version of the software.  You can elect to have both the
 README.1st and README.11b 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 3.5. 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. 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.


ΓòÉΓòÉΓòÉ 3.6. Formatting VDUs with AutoFormat ΓòÉΓòÉΓòÉ

The VDUs you created during the install are unformatted until your system
restarts; then the DCF/2 uses the OS/2 format command to format each of them as
HPFS drives.

The format uses an "undocumented OS/2 2.1 feature" [--] the NOF switch [--] for
fast format.  The formatting process can take from a few seconds using the
switch to a couple of minutes without it, 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.


ΓòÉΓòÉΓòÉ 3.7. 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 3.8. Formatted, Clean and Ready for Data ΓòÉΓòÉΓòÉ

The DCF/2 startup continues, the DCF/2 Space Manager is launched for each VDU
and the Workplace Shell comes up.  At this point, your VDUs are formatted,
empty and available.  You may now begin to move data and user files onto them
[--] using the tools you normally use to move directories and files on your
system.


ΓòÉΓòÉΓòÉ 3.9. DCF/2 OS/2 System Shutdown Program ΓòÉΓòÉΓòÉ

During the DCF/2 installation, a DCF/2 Shutdown icon was placed on your OS/2
Desktop.  By using the DCF/2 System Shutdown instead of the normal OS/2
Shutdown, you do two things:  First, you insure that all of your VDUs are
shutdown properly and that the shutdown process continues through the final
Control-Alt-Delete box.

Second, by using the DCF/2 System Shutdown, you by pass the DCF/2 AutoCheck
feature at system startup.  Depending upon the number of VDUs you have and
their size, the auto CHKDSK /F process can be a time consuming one.  It's time
you can save by using the DCF/2 System Shutdown program.

Optional Parameters for Shutdown

The following optional parameters are available for the SHUTDOWN.EXE program
shipped with the DCF/2 and can be added to the optional parameters line in the
DCF/2 System Shutdown program's settings notebook on your desktop:

     Parameter      Function
     /i             Interactive shutdown.  Prompts you to answer yes/no to
                    cancel shutdown.
     /n             No system shutdown.  Shuts down the DCF2ACP only.
     /t             "Thinkpad" or the like.  This optional parameter doesn't
                    kill processes, but shuts down the DCF2ACP.EXE and system.
     /s             Single click shutdown.  On some systems, this may result in
                    an infinite shutdown loop!
     /d:            Default time in seconds for the Shutdown Countdown.  The
                    default is 10 seconds.  Increase this number if your do not
                    reach the final C-A-D box at shutdown.
     /w:            Smallest Process ID number (detached processes) in a range
                    of PIDs to "kill" at shutdown.
     /W:            Largest Process ID number (detached processed) in a range
                    of PIDs to "kill" at shutdown.

 For additional information on the DCF/2 OS/2 System Shutdown program, please
 refer to the section on the program in the User Reference.


ΓòÉΓòÉΓòÉ 3.10. 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 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

 Important:  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.

 The client workstation then installs the DCF/2 from the temporary directory,
 by changing to the temporary directory and running the DCF/2 install program.

     X:\TMP\INSTALL


ΓòÉΓòÉΓòÉ 3.11. Updating Workstations from a Network 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.  This process can
be done directly from the central server and does not require that the client
workstation logoff the network at any time during the procedure.


ΓòÉΓòÉΓòÉ 3.12. Registration & Unlicensed Copies 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.

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 required.

If this copy of the DCF/2 is an unregistered copy -- one not purchased -- it
will "sing".  The sound is our "nagware."  While we wish to give those who feel
they need an opportunity to "try before you buy," the opportunity to do so, the
DCF/2 is neither "shareware" nor "freeware" but licensed software.  To license
it one must purchase it.  See the second page of the REMINDER.LOG generated in
your in the root directory of your boot drive for information on purchasing the
DCF/2.

If your licensed copy of the DCF/2 continues to sing, we apologise.  Please
contact technical support at your earliest convenience.

Telephone technical support is available to registered users only and is
reached by calling [phone] between the hours of 8 a.m and 4 p.m U.S.
Mountain Time

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).


ΓòÉΓòÉΓòÉ 4. 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.

The DCF/2 is a full 32-bit program for OS/2 2.X.  The DCF/2 supports all OS/2
file systems as host storage for compressed, HPFS-formatted virtual disk units
(VDUs), so long as you are running OS/2 2.11 or greater.  For users running
OS/2 2.0, OS/2 2.1 or or OS/2 for Windows, only FAT-based host storage is
supported.  For the  OS/2 2.11 user, the 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.

The DCF/2 is a system of building blocks designed to grow with your entire
operating environment - IBM's OS/2 2.1 32-bit multitasking makes it all
possible!

The following topics are covered in this section:

     o Product Architecture
     o How It Works
     o What is a "VDU"?
     o Compression


ΓòÉΓòÉΓòÉ 4.1. 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.  Third-party developers
can add compression, encryption, and other disk related capabilities to your
system environment (contact the PSC technology lab for pricing and details of
the DCF/2 CDE API kit).


ΓòÉΓòÉΓòÉ 4.2. How It Works ΓòÉΓòÉΓòÉ

When the OS/2 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 compressed disk requests are processed and managed by standard OS/2
disk and file services.  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 VDU Control Process initializes all VDUs during OS/2 system startup
and then launches the DCF/2 space manager.  The latter monitors the amounts of
virtual and physical space in use to prevent the user from running out of
physical space on the host volume.

The DCF/2 benefits from all OS/2 file and memory management features, so that
applications 'see' the DCF/2 VDU as a "real" disk.

The DCF/2 takes advantage of the OS/2 High Performance File System, allowing
DCF/2 VDU's to utilize all of its advanced features like 255 character file
names, integrated extended attributes, and support for HUGE disks.


ΓòÉΓòÉΓòÉ 4.3. What is a "VDU"? ΓòÉΓòÉΓòÉ

"VDU" is short for "Virtual Disk Unit."  If you think in terms of the types of
drives you work with, they are usually either "physical" or "logical."

A physical drive is one you can reach out and touch. You use low level
utilities, like FORMAT and CHKDSK, on a physical drive.  A network drive is an
example of a logical disk unit.  You cannot touch it.  And you cannot run low
level utilities, like FORMAT and CHKDSK, on it.

A "Virtual Disk Unit" is a cross between the two.  Like a network drive, it is
logical rather than physical.  Like a physical drive, you use low level
utilities, like FORMAT and CHKDSK, on it.

In reality, a VDU is a flat, simple file with no EAs (extended attributes), in
which your data is stored 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 4.4. 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.  In addition, the DAT keeps track of the compression type performed on
each compressed chunk and how many times the chunk has been accessed,
compressed, and/or decompressed.  Your VDU develops a  personality of its own
as it matures, based upon the way you use it.

What to Compress

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 space storing the data on a virtual disk unit will return to you.

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.  OS/2 MDOS and WINOS2
program compress at about 1.81:1.  Game files compress poorly at 1.5:1.

What Not to Compress

Some files should not be compressed at all.  For example, 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.)

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.

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

Compressing OS/2 Itself

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 are loaded.  The DCF/2 physical device driver
(DCF2PDD.SYS) loads at this time.

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). The DCF/2 ancillary
control process (DCF2ACP.EXE) and its associated support processes load at this
time.

Those parts of OS/2 required prior to the time when OS/2 loads the DCF/2 device
drivers and executes the CALL statement to startup the DCF/2 cannot be stored
on a compressed drive.

Our recommendation is that you allocate to OS/2 the space it requires and
compress your applications software, utilities, user files and things like
icons, clipart and communications threads, etc.

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 8MV
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 EPD (the Enhanced Editor) and OS/2 reference files (.INF) to a
VDU.


ΓòÉΓòÉΓòÉ 5. DCF/2 and Your 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, formatting
and/or running CHKDSK on any VDUs that are either unformatted or were left
"dirty" by an improper shutdown, and launching the space manager.

If your system is improperly shutdown, e.g., you turn it off without running
the DCF/2 System Shutdown program, you have a power failure, or your system
experiences a trap or the system hangs necessitating a reboot, the DCF/2 will
automatically run CHKDSK /F on each VDU during the OS/2 boot process.  This
checks your VDUs for errors and makes the necessary repairs.  It keeps you from
causing further damage to a damaged VDU.

You can use CONTROL-C to terminate the AUTOCHECK process.  However, as a
safeguard, the VDU remains "dirty" until you run CHKDSK /F on it -- even if you
run a proper shutdown using the DCF/2 System Shutdown.

If you find you want to interrupt the startup process, you can.  When prompted,
depress the CONTROL key to interrupt the startup process and exit to an OS/2
command processor.  To resume the startup process, type "EXIT".

Far less often, you may find you need to keep the DCF/2 from loading at all. To
abort the DCF/2 load, depress one or both SHIFT key(s) when prompted to do so.
OS/2 will not load the DCF/2 device drivers.  Note:  Your VDUs will not be
available until you restart your system.

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

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


ΓòÉΓòÉΓòÉ 5.1. The DCF/2 Device Drivers ΓòÉΓòÉΓòÉ

The DCF/2 is not designed as an IFS (installable file system).  The DCF/2
install program placed two two device drivers in your CONFIG.SYS file.  OS/2
loads these at system startup.

The DCF2PDD

The DCF/2 Physical Device driver defines a block device in your  CONFIG.SYS
that "creates" your compressed drive.  It must load in your  CONFIG.SYS prior
the DCF2CDE.SYS.

The DCF2CDE

The DCF/2 Compression Decompression Engine (DCF2CDE.SYS) is a  character-based
device driver.  As requested data is passed to it, it  compresses or
decompresses that data and passes it on.


ΓòÉΓòÉΓòÉ 5.2. The DCF/2 Control Program ΓòÉΓòÉΓòÉ

The DCF/2 Control Program (DCF2.EXE) is the command line interface for the
DCF/2 on non-PM systems.  It will also be used on a PM system if you want to
create or remove VDUs once you have installed the DCF/2 and created your
initial VDUs.

The CALL statement the DCF/2 install program inserted at the end of your
CONFIG.SYS, calls the DCF/2 control program, which in turn lauches the DCF2ACP
and DCF2VCP programs.

Refer to the appendix for a list of DCF2.EXE commands and parameters.


ΓòÉΓòÉΓòÉ 5.3. The DCF/2 VDU Control Process ΓòÉΓòÉΓòÉ

The DCF/2 VDU Control Process (DCF2VCP) performs two functions.  First, it
creates the control processes run during your system's startup.  It initializes
the disks.  Then, during run-time, it controls space management for each VDU
using the DCF2INFO.CMD file.

Space Management File

Each VDU has a DCF/2 Space Manager File, DCF2INFO.CMD.  This file reports the
VDU's current compression ratio and available compression ratio after
recompaction.  This file also reports the total size of, amount of space in use
by and space available for both the VDU's physical host drive and for the VDU
itself.

The purpose of this file is to protect you from running out of physical space
on the VDU's host drive [--] a condition which can jeopardize the integrity of
the VDU.  The file may appear to be very large at times.  In reality, it
occupies very little space and is stored in the VDU's Disk Allocation Table in
single-byte entries.

To display the file, go to an OS/2 command prompt and type the VDU drive letter
followed by a colon and DCF2INFO, e.g., X:DCF2INFO.  If you are not in the
root, use \X:DCF2INFO, where X is the drive letter for the VDU.  To exit, type
Control-C.


ΓòÉΓòÉΓòÉ 5.4. The DCF/2 Ancillary Control Process ΓòÉΓòÉΓòÉ

The DCF/2 Ancillary Control Process (DCF2ACP) is the software controller for
the virtual disk drive.  It connects drive letter X to the VDU container file.
For example, you might have a VDU drive letter E: and a VDU container file
C:\DCF2\DCF2_E.VDU.  The DCF2ACP "connects" the two.

While you will need to do so only seldom [--] for example, to delete a VDU
container file or to update the DCF/2 program files [--] you can easily stop
and start the DCF2ACP using the DCF/2 Control Program.  To try it, change to
your DCF2 program directory, type DCF2 /A:SHUTDOWN to stop the DCF2ACP and DCF2
/A:STARTUP to restart it.

Note:  If the DCF2ACP is stopped, your VDUs and the programs and data on them
       are not available.  This makes sense if you think in terms of your
       physical disk controller [--] were you pull your physical disk
       controller out of your computer, the programs and files on your physical
       disk would not be available.


ΓòÉΓòÉΓòÉ 6. OS/2 File Systems ΓòÉΓòÉΓòÉ

A file system determines how data is stored on your disk.  OS/2 supports two
basic file systems:  FAT and HPFS.  The key difference between the two file
systems is the way in which they manage the date stored on your disk.

The following topics are covered in this section:

     o The FAT File System
     o The HPFS File System
     o HPFS vs. FAT Summary
     o Floppies
     o DCF/2 and the OS/2 File Systems
     o Physical Drive Management
     o Virtual Drive Management
     o Backing Up


ΓòÉΓòÉΓòÉ 6.1. The FAT File System ΓòÉΓòÉΓòÉ

The FAT file system stores data using clusters.  The size of the cluster used
depends upon the size of the drive.  Typically, the cluster size is 4 Kbytes;
but as the size of the drive increases, the size of the cluster increases to 8
or even 16Kbytes.  This increase is due to the limitation on the maximum number
of entries that can be supported by the File Allocation Table (64K entries).

The FAT 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 a three alphanumeric characters.


ΓòÉΓòÉΓòÉ 6.2. The HPFS File System ΓòÉΓòÉΓòÉ

The High Performance File System or HPFS stores data at sector granularity [--]
512 bytes per sector.  The HPFS includes sophisticated caching and lazy writing
mechanisms.  Finally, the HPFS employs an extremely efficient mechanism for
searching.

It supports file names up to 254 characters in length, providing the user with
the ability to use far more descriptive file names than the eight character
plus three character extension available using FAT.


ΓòÉΓòÉΓòÉ 6.3. HPFS vs. FAT Summary ΓòÉΓòÉΓòÉ

Statistically over a FAT formatted drive, one half of the cluster size is lost
in slack space.  Actually, it can be worse than that [--] especially if you
have a lot of small files, like icons.  An icon is typically slightly less than
1Kbytes big, but a FAT-formatted partition, with a minimum cluster size of
4Kbytes will require 4Kbytes to store this 1Kbyte file.  If you store 4,000 1K
big icon files on a FAT partition, you will use 16MB [--] 12MB of the 16MB are
lost in slack space!

On an HPFS-formatted drive, to store the same 1K icon file requires only 1024
bytes.  To store the same 4,000 1Kbyte big icon files that required 16MB on a
FAT-formatted partition, requires only 4 MB!

The HPFS also offers several other benefits.  Among these are a highly
efficient binary-tree search mechanism, 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.  It is always formatted to use the File
Allocation Table.  Using the DCF/2, you can put HPFS-formatted VDU's on
FAT-based floppy devices.


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

DCF/2 VDUs are formatted using the OS/2 High Performance File System (HPFS).
Based upon extensive comparisons of the two file systems, we have concluded
that an HPFS-formatted drive is faster and more efficient than the equivalent
size FAT (File Allocation Table) formatted drive -- independent of the size of
the drive.


ΓòÉΓòÉΓòÉ 6.6. Physical Drive Management ΓòÉΓòÉΓòÉ

It is important to take 'good care' of your physical disk storage before doing
anything with DCF/2 virtual disk units.  This is because the virtual disk units
reside on physical storage and if it is not correct, that can cause unnecessary
risk to the virtual disk container file.

In most cases, the only thing you have to do to maintain your physical disk
integrity, it to make sure you 'AUTOCHECK' your physical disk drives at startup
time.  The DCF/2 installation procedure automatically insures this by
correcting the IFS= and DISKCACHE= CONFIG.SYS statements, if the AUTOCHECK
option is not already there.

If you do experience a physical disk integrity problem make sure you properly
shutdown (using the DCF/2 provided shutdown icon or SHUTDOWN.EXE program) and
then make sure that the CHKDSK operation is performed during system restart.


ΓòÉΓòÉΓòÉ 6.7. Virtual Drive Management ΓòÉΓòÉΓòÉ

DCF/2 virtual disk units should be treated exactly as you do physical disk
units, except (as noted above) that the physical disk management MUST be
performed BEFORE any DCF/2 virtual disk maintenance.


ΓòÉΓòÉΓòÉ 6.8. Backing Up ΓòÉΓòÉΓòÉ

The DCF/2 virtual disk units offer you a great deal of backup flexibility.

You can backup the VDU container file itself and have an 'image' backup of the
compressed volume.

You can backup the individual files in the VDU and have file-by-file backup of
your compressed storage.  This method provides an uncompressed copy of each
file in the VDU's compressed storage.

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


ΓòÉΓòÉΓòÉ 7. DCF/2 User Reference ΓòÉΓòÉΓòÉ

The User Reference is divided into the following sections, which describe the
functions and operations of the DCF/2 program modules.

     o System Startup
     o DCF/2 Control Program (DCF2.EXE)
     o DCF/2 Ancillary Control Process (DCF2ACP.EXE)
     o DCF/2 VDU Control Process (DCF2VCP.EXE)
     o DCF/2 Monitor (DCF2MON.EXE)
     o DCF/2 Shutdown Program
     o DCF/2 OPTIMIZE (Recompaction) Utility
     o DCAT (Disk Compression Analysis Tool)
     o Moving Files from Physical to Virtual Space


ΓòÉΓòÉΓòÉ 7.1. System Startup ΓòÉΓòÉΓòÉ

During system startup, the DCF/2 is linked to the OS/2 operating system to
provide transparent access to your virtual, compressed disk storage.

The HPFS.IFS

The DCF/2 relies on the OS/2 High Performance File System (HPFS) for all
virtual disk operations.  Normally the IFS= CONFIG.SYS statement will be at the
beginning of your system startup.

The DCF/2 Device Statements

The DCF/2 virtual disk "block devices" are created when OS/2 loads the
DCF2PDD.SYS device driver.  The "/U:" option determines how many template
virtual disk units are created.  These are associated with virtual disk unit
container files using environment strings (see below).

The DCF/2 Environment Strings

The DCF/2 associates a virtual drive unit with it's container file using a
process environment string of the form:  DCF2_VDU_x=full_file_path, where "x"
is the VDU drive letter to be associated with "full_file_path" file name.  A
full file path is normally "d:\dir\filename.ext."

The CALL=DCF2.EXE

The DCF/2 is actually started, normally, at the very end of the system
CONFIG.SYS using the CALL= startup statement.  During DCF/2 startup, the system
startup can be interrupted or aborted as described during system startup.

Using Startup.CMD instead of CALL=DCF2.EXE

If you have placed DCF/2 VDUs on network drives which are not available during
system startup, move the "CALL=DCF2 /A:STARTUP" statement from the CONFIG.SYS
to your STARTUP.CMD file.  Place it in the STARTUP.CMD after the statements
that start your network software.


ΓòÉΓòÉΓòÉ 7.2. The DCF/2 Control Program (DCF2.EXE) ΓòÉΓòÉΓòÉ

You can add or remove drive letters and create VDU's using the DCF/2 control
program.  Refer to the Appendices for a list of the program's commands and
switches.

Add a VDU

In the example outlined below, we will add a third VDU, (G:) with a size of 100
MB.  The process has two steps.  First, we will will make two edit changes to
the DCF/2 statements in the CONFIG.SYS.  Second, we will use the DCF/2 Control
Program to create the VDU.

Add a VDU Drive Letter

First, we need to edit /:u pararmeter following the DCF/2 physical device
driver statement in the CONFIG.SYS file.  The /:u dictates the total number of
VDU drive letters.  To add one VDU drive letter, we will increase this number
by 1.

Say, for example, our system has a physical drive C: with a logical partition
D: and we created two VDUs when we installed the DCF/2.  These are drives E:
and F:.  Currently, the /:u parameter is the number 2.  When we add the next
VDU drive letter, we increase this number goes up by 1 to the number 3.  Now
our system has VDU drive letters E:, F:, and G:.

At this point, we have a new drive letter, G:, but nothing points to it until
we add an environment string to associate G: with the VDU container file.
(Have patience, we will create the VDU container file next, using the DCF/2
Control Program after the next step.)

Let's continue using the system from the example from above.  The environment
strings in the CONFIG.SYS look like the following:

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

 Say we want our new VDU G: to reside on D:.  The environment statement will
 look like this:

     SET DCF2_VDU_G=D:\DCF2\DCF2_G.VDU

 Create the VDU Container File

 Having made the necessary changes to the CONFIG.SYS, we are ready to use the
 DCF/2 Control Program to create the VDU.  When we added the environment string
 to the CONFIG.SYS file, we gave the container file the following path and file
 specification:  D:\DCF2\DCF2_G.VDU.

 To create the VDU, change to the DCF2 program directory.  Use the following
 command to create our 100MB VDU G:

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

 The parameters used above are /V: (Virtual Disk Unit), /S: (Size in MB) and
 /F: (Path and File Specification).

 Restart the Computer

 The final step in the process is to restart the computer system.  This
 initializes the changes made to the CONFIG.SYS and runs FORMAT on the new VDU.

 Deleting a VDU

 In the event you want to remove a VDU, the procedure involves three steps.

 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.

 Remove the VDU Drive Letter

 To remove the VDU drive letter, you edit the DCF/2 statements in your
 CONFIG.SYS.  First, look for the /u: parameter following the DCF2PDD.SYS and
 reduce the number by 1.

 Next remove from the CONFIG.SYS the SET statement which points to your last
 drive letter, e.g., SET DCF2_VDU_G=D:\DCF2\DCF2_G.VDU

 Save the change and exit from the CONFIG.SYS.

 Delete the VDU Container File

 To delete the VDU, change to the DCF2 program directory.  Use the DCF2 /- to
 stop the DCF2ACP.

     DCF2 /A:SHUTDOWN

 To protect you from inadvertantly deleting your VDU(s), we set the system
 attribute.  For DELETE to access a VDU, you must remove this attribute:

     ATTRIB *.VDU -S

 Use the DELETE command to delete the VDU container file.  In the case of the
 system described in the section on adding a VDU, the last VDU is G:.  The
 following command would delete the file:

     DELETE DCF2_G.VDU /V

 Restart the Computer

 As always, changes to the CONFIG.SYS are only initialized after the computer
 is restarted.


ΓòÉΓòÉΓòÉ 7.3. DCF/2 Ancillary Control Process (DCF2ACP.EXE) ΓòÉΓòÉΓòÉ

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.

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 to a greater
degree.  You can do so by removing the REM >> from the DCF2ACP logging
statement in your CONFIG.SYS and reboot.  Or you can issue the following SET
command:

     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 out weighs 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. DCF/2 VDU Control Process (DCF2VCP.EXE) ΓòÉΓòÉΓòÉ

The DCF2VCP manages the virtual disk units you create using the controller
(DCF2ACP).  During system startup, the DCF2VCP initializes your VDUs and
launches the DCF2ACP and Space Manager.

Any DCF/2 VDU Control Process error conditions are reported in the DCF2VCP.LOG
file created in the root of your OS/2 boot drive.  If you experience a problem
during system startup, you may want to enable DCF2VCP logging to a greater
degree.  You can do so by removing the REM >> from the DCF2VCP logging
statement in your CONFIG.SYS and reboot.  Or you can issue the following SET
command:

     SET DCF2_VCP_LOGNG=3
     SET DCF2_VCP_DEBUG=3


ΓòÉΓòÉΓòÉ 7.5. DCF/2 Monitors (DCF2MON.EXE) ΓòÉΓòÉΓòÉ

The monitors are LED icons -- one for each VDU you create.  They flash to
indicate drive activity.  Monitor LEDs flash red for write and blue for read
operations.  They flash green during compression and yellow during
decompression.

If you need to create a VDU LED manually, do the following:

      1. Use the drives icon to open the DCF2 program directory.
      2. Locate the DCF2MON.EXE icon in the DCF2 program directory.
      3. Drag the icon to your Startup folder.  (Control+Right Mouse Button)
      4. Open the settings notebook for the icon.
      5. Go to the parameters box on the program setting page.
      6. Enter /l:X, where X is the VDU drive letter.
      7. Close the settings notebook.
      8. Double click on the VDU LED to put it on your desktop.

 You can move the icon to a specific location on your desktop and save that
 location so that when you restart your system, the icon comes up in that
 location.  To do so, drag the icon to the desired location.  Double click on
 the icon to close it.  Reboot your system.  The icon's location coordinates
 are now saved.

 You can make your VDU LEDs larger.  Click the minimize button on the LED.  The
 icon disappears from the desktop and reappears in your minimized window viewer
 -- bigger.

 Hint   If you double click on an LED icon in your Startup Folder and the
 Window List pops up, look for the LED icon in your Minimized Window Viewer.

 The following are optional parameters for DCF2MON.EXE. and are specified in
 the parameters box in the LED icon's settings notebook on the program settings
 page.

     Parameter                            Function
     /l:X                                 VDU Drive letter for this LED icon.
     /x: followed by a decimal value.     Designates the x coordinate location
                                          of the LED icon on your Desktop.
     /y: followed by a decimal value.     Designates the y coordinate location
                                          of the LED icon on your Desktop.
     /t: followed by time in seconds.     Establishes the refresh frequency for
                                          the LED icon.  Increase this if you
                                          feel the monitor refreshes are
                                          loading your system.  (Applies to
                                          certain video adaptors.)


ΓòÉΓòÉΓòÉ 7.6. DCF/2 Shutdown Program ΓòÉΓòÉΓòÉ

During the DCF/2 installation, a DCF/2 Shutdown icon was placed on your OS/2
Desktop.  By using the DCF/2 System Shutdown instead of the normal OS/2
Shutdown, you do two things:  First, you insure that all of your VDUs are
shutdown properly and that the shutdown process continues through the final
Control-Alt-Delete box.

Second, by using the DCF/2 System Shutdown, you by pass the DCF/2 auto-check
feature at system startup.  Depending upon the number of VDUs you have and
their size, the auto CHKDSK /F process can be a time consuming one.  It's time
you could have saved by using the DCF/2 System Shutdown program.

The DCF/2 OS/2 System Shutdown broadcasts a message to all PM applications --
regardless of whether they are running from virtual or physical storage.  If
this causes you problems when your system restarts, you may need to add those
running on your VDUs to your STARTUP Folder.

Optional Parameters for Shutdown

The following optional parameters are available for the SHUTDOWN.EXE program
shipped with the DCF/2.  Most of these, you will never have call to use.  They
can be added to the parameters box on the program settings page of the DCF/2
System Shutdown icon's Settings Notebook on your Desktop:

     Parameter      Function
     /i             Interactive shutdown.  Prompts you to answer yes/no to
                    cancel shutdown.
     /n             No system shutdown.  Shuts down the DCF2ACP only.
     /t             "Thinkpad" or the like.  This optional parameter doesn't
                    kill processes, but shuts down the DCF2ACP.EXE and system.
     /s             Single click shutdown.  On some systems, this may result in
                    an infinite shutdown loop!
     /d:            Default time in seconds for the Shutdown Countdown.  The
                    default is 10 seconds.  Increase this number if your do not
                    reach the final C-A-D box at shutdown.
     /w:            Smallest Process ID number (detached processes) in a range
                    of PIDs to "kill" at shutdown.
     /W:            Largest Process ID number (detached processed) in a range
                    of PIDs to "kill" at shutdown.

 Important   If you use Dual Boot, add the /n parameter to the SHUTDOWN.EXE
 under Parameters in the settings notebook for the DCF/2 System Shutdown icon.
 Use the icon to shutdown the DCF/2 first and then use your Dual Boot icon.

 The DCF/2 installation program put an OS/2 System Shutdown icon on your
 desktop.  If you are truly addicted to running shutdown using the right mouse
 button, we suggest that you add the DCF/2's OS/2 System Shutdown as an item on
 your desktop menu.  To do so:

      1. Click the right mouse button to pop-up the Desktop menu.
      2. Click on OPEN.
      3. Click on SETTINGS.
      4. Click on MENU.  You will see a box labelled:  "Actions on Menu:
         Primary Pop-up Menu."
      5. Locate the DCF/2 OS/2 System Shutdown icon on your Desktop and drag it
         the box described in the proceeding step.
      6. Close the settings notebook.


ΓòÉΓòÉΓòÉ 7.7. The DCF/2 OPTIMIZE (Recompaction) Utility ΓòÉΓòÉΓòÉ

Note:  Your VDU(s) and the programs and data on them are not available to you
       during this process.  The length of time required to recompact a VDU
       will vary with speed of your computer processor and the size of the VDU.
       Refer to the tables below to determine how much time to allow to
       recompact the VDU(s) on your computer system.

 The Optimizer (DCF2PAKR) is the program you will run when you want to purge
 your VDU(s) of deleted space and compress to maximum the data stored in it.
 While it can be, it is not necessary to run this program on a daily basis
 [--]once a week should be sufficient.

 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

 Optimizing a VDU involves four steps:  Purging the VDU(s), stopping the
 DCF2ACP, optimizing the VDU(s) and then restarting the DCF2ACP.

 Purging VDUs

 Purging removes deleted space from VDU(s).  You purge a VDU prior to
 optimizing it.

 To purge VDU E: you use the following command in which the /P parameter means
 PURGE and /V: is following by the drive letter of the target VDU:

     DCF2PAKR /P /V:E

 Stopping the DCF/2 in Preparation to Optimize VDUs

 Before you can proceed to OPTIMIZE your VDUs, you must first stop the DCF2ACP.
 To do so, use the following command:

     DCF2 /A:SHUTDOWN

 Remember that your VDUs and the data on them will not be available until you
 restart the DCF2ACP.

 Recompressing VDUs

 You OPTIMIZE your VDU(s) only after you have purged them of deleted space.
 This process will recompress each chunk of compressed data stored in the VDU
 at its maximum compression.

 To optimize VDU E: you use the following command in which the /O parameter
 means OPTIMIZE and /V: is following by the drive letter of the target VDU:

     DCF2PAKR /O /V:E

 Converting DCF/2 Version 1.1a to Version 1.1b Formats

 Users with existing VDUs formatted under DCF/2 Version 1.1a should refer to
 the appropriate appendix for the procedure to follow in order to convert VDUs
 created using version 1.1a to the format used in version 1.1b.


ΓòÉΓòÉΓòÉ 7.8. The DCAT (Disk Compression Analysis Tool) ΓòÉΓòÉΓòÉ

The DCF/2 comes with a powerful, statistical Disk Compression Analysis Tool
(DCAT) which allows you to measure file compressibility before moving those
files into your DCF/2 virtual disk units.

The DCAT in an interactive, OS/2 Presentation Manager application with full
online help (F1, or HELP button).  To run the DCAT, change to the DCF2 program
directory and type:  DCAT.


ΓòÉΓòÉΓòÉ 7.9. Moving Files from Physical to Virtual Space ΓòÉΓòÉΓòÉ

You can use any of your existing DOS, Windows, or OS/2 program utilities to
move, copy, delete, and maintain your DCF/2 VDU files.

Using XCOPY and DELETE

When using XCOPY to copy files into a VDU, it is recommended that you include
the '/f' and '/e' command line switches to insure that the existing file
extended attributes are copied from the physical disk unit.  See the OS/2
online help for XCOPY for additional switches.

Using the Drives Icon

The OS/2 DRIVES icon provides you with a powerful Presentation Manager utility
which 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!

Be aware, when moving program objects, that there may be LIBPATH, PATH, and
DPATH references to those program objects which may not be updated.

If you have very little physical space available on the host and use the drives
icon, be careful.  The drives icon move seems to move files in large chunks,
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.  Go slowly.

Hint  :  Including applications stored on a VDU in the LIBPATH statement in
your CONFIG.SYS is somewhat problematic.  If the AutoCheck function hasn't
completed and your VDUs are not yet available to OS/2, it can cause the system
to lock up.  The workaround is to create the identical subdirectory on a
physical disk unit and move all of the program in questions DLLs to the
subdirectory on the PDU.  Then change the LIBPATH to point to the subdirectory
on the PDU.


ΓòÉΓòÉΓòÉ 8. VDU Maintenance & Troubleshooting ΓòÉΓòÉΓòÉ

Because of the auto-checking built into the DCF/2 startup process, you won't
normally need to spend a great deal of your time checking your physical and
virtual space.

     o Checking Physical Space
     o Checking Virtual Space
     o VDU OPTIMIZE (Recompaction) Utility
     o Troubleshooting


ΓòÉΓòÉΓòÉ 8.1. Checking Physical Space ΓòÉΓòÉΓòÉ

THE CARDINAL RULE FOR VDU MAINTENANCE IS: ALWAYS RUN CHKDSK ON THE PHYSICAL
DRIVE FIRST.  If you suspect that the VDU's physical or host drive is
corrupted, you MUST run CHKDSK (FAT) or CHKDSK /F (HPFS) on the physical drive
to prevent damaging the VDU.

You will use CHKDSK on FAT-based physical disk units and CHKDSK /F on
HPFS-based physical disk units.  If you are unfamiliar with this program,
please refer to OS/2's online help.


ΓòÉΓòÉΓòÉ 8.2. Checking Virtual Space ΓòÉΓòÉΓòÉ

Because a VDU looks physical to OS/2, it requires no special utilities beyond
those supplied with OS/2.  In this case, that is the CHKDSK program. The
program will correct any space allocation errors and remove any corrupted files
in the VDU, placing them in the FOUND directory as .CHK files if you so choose.

Run CHKDSK /F on your VDUs only after you have CHKDSK'ed the physical or host
drive or are absolutely certain that the host drive is "clean."  When you
startup your system, the DCF/2 does this for you.

If you are unfamiliar with this program, please refer to OS/2's online help.


ΓòÉΓòÉΓòÉ 8.3. VDU OPTIMIZE (Recompaction) Utility ΓòÉΓòÉΓòÉ

Once a week or as you feel it necessary, run the DCF2PAKR program on each of
your VDUs to purge them of deleted space and optimize them.  During this
process each chunk of data stored in the VDU is recompressed.  Generally, you
will recover about 10% of the space in the drive.

The DCF2INFO file for each VDU reports the both the current compression ratio
for the VDU and the estimated compression ratio after the next recompaction.

The process involves four steps:  The first step zeros out deleted and lost
space on the drive.  We call this "purging."  It does not purge data from your
VDU -- only free space.  The DCF2 must be running during the purge function.
Once the purge function is complete, the second step is to stop the DCF2 --
refer to the Appendix for the command and switch to use.  The third step is to
optimize the drive.  This decompresses and recompresses each chunk of data on
your VDU.  The fourth step is to restart the DCF2.

      1. Purge your VDU of deleted space using the DCF2PAKR command:  DCF2PAKR
         /p /v:x
      2. Stop the DCF2 using the DCF2 command:  DCF2 /A:Shutdown
      3. Optimize your VDU using the DCF2PAKR command:  DCF2PAKR /o /v:x
      4. Restart the DCF2 using the DCF2 command:  DCF2 /A:Startup

 The commands are executed on an OS/2 window or full screen, from the DCF2
 program directory.  In the above example, the DCF2PAKR command options are:
 /p (purge), /v:x (The VDU drive letter to be purged, e.g. VDU X) and /o
 (optimize).

 You can create a batch file to purge and optimize your VDU(s) and launch it
 from OS/2's ALARMS applet or from a package like RELISH for OS/2.  Just
 remember to purge all VDUs, then shutdown the DCF2, and then optimize all VDUs
 before starting the DCF2 again.

 For additional information please refer to the first section in the Appendix
 "DCF/2 Command Reference."


ΓòÉΓòÉΓòÉ 8.4. Troubleshooting ΓòÉΓòÉΓòÉ

The first place to look to diagnose the cause of a suspected problem is the
logfiles, DCF2ACP.LOG and DCF2VCP.LOG in the root of your boot drive.

The prescribed remedy whenever you suspect a 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.

 Do not panic if the DCF/2 AutoCheck during startup or CHKDSK /F from an OS/2
 command processor report frightening sounding error messages about not finding
 but attempting to reconstruct the root directory for a virtual drive.  Let
 CHKDSK run and repair any damage.  Then run it again and again until it
 reports no errors.  You may have some work to do to rename the FOUND
 directories and CHECK 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.

 If the CHKDSK /F program creates FOUND directories, it may, in its infinite
 wisdom place a renamed copy of your VDU's DCF2INFO.CMD space management file
 in one of these FOUND directories.  This file may appear to occupy a great
 deal of space.  Find it and delete it.


ΓòÉΓòÉΓòÉ 9. Appendix ΓòÉΓòÉΓòÉ

 The Appendix contains the following sections:

     o DCF/2 Command Reference
     o DCF/2 VDU Optimize Utility
     o OS/2 System Shutdown Parameters
     o DCF/2 Monitor Parameters
     o Converting Version 1.1a to Version 1.1b
     o Using the DCF/2 and Netware
     o Hints for Running Your Application from a VDU
     o Tips & Techniques
     o Cache Considerations


ΓòÉΓòÉΓòÉ 9.1. DCF/2 Command Reference ΓòÉΓòÉΓòÉ


DCF2 Control Program Command Line Parameters

ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
ΓöéCommand ΓöéParameter             ΓöéFunction                                Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
ΓöéDCF2    Γöé/A:STARTUP            ΓöéStarts the DCF/2 Control Processes.     Γöé
Γöé        Γöé                      ΓöéMakes your VDUs available.              Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
ΓöéDCF2    Γöé/+                    Γöé"Shorthand" method to start the DCF/2   Γöé
Γöé        Γöé                      ΓöéControl Processes.                      Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
ΓöéDCF2    Γöé/A:Startup /D         ΓöéStarts the DCF/2 Control Processes and  Γöé
Γöé        Γöé                      Γöésays to delete the DCF2INFO.CMD at      Γöé
Γöé        Γöé                      Γöéstartup.  Use this option if you run    Γöé
Γöé        Γöé                      Γöévirus scanning software.  It will       Γöé
Γöé        Γöé                      Γöéeliminate uncecessary scanning time.    Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
ΓöéDCF2    Γöé/A:STATUS             ΓöéReports the Status of the DCF/2 Control Γöé
Γöé        Γöé                      ΓöéProcesses (currently running or         Γöé
Γöé        Γöé                      Γöécurrently not running).                 Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
ΓöéDCF2    Γöé/A:SHUTDOWN           ΓöéStops the DCF2 Control Processes.  Your Γöé
Γöé        Γöé                      ΓöéVDUs are unavailable when you stop the  Γöé
Γöé        Γöé                      ΓöéDCF/2.  Use this command before you     Γöé
Γöé        Γöé                      ΓöéOPTIMIZE a VDU or if you need to delete Γöé
Γöé        Γöé                      Γöéa VDU.                                  Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
ΓöéDCF2    Γöé/-                    Γöé"Shorthand" method to stop the DCF/2    Γöé
Γöé        Γöé                      ΓöéControl Processes.                      Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
ΓöéDCF2    Γöé/V:CREATE /S: /F:     ΓöéCreates VDU of /S:[size in megabytes]   Γöé
Γöé        Γöé                      Γöéand /F:[file specification]  (The path  Γöé
Γöé        Γöé                      Γöéand filename for the VDU container      Γöé
Γöé        Γöé                      Γöéfile.)                                  Γöé
Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
ΓöéDCF2    Γöé/R:X                  ΓöéRefreshes the DCF2INFO file for VDU "X."Γöé
Γöé        Γöé                      Γöé(Wait 15 seconds before typing the next Γöé
Γöé        Γöé                      ΓöéX:DCF2INFO.)                            Γöé
ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ

From an OS/2 window or full screen, you can change to the DCF2 program
directory and type DCF2 for a list of DCF/2 Control Program commands and
switches.


ΓòÉΓòÉΓòÉ 9.2. DCF/2 VDU Optimize Utility ΓòÉΓòÉΓòÉ

Note:  If multiple VDUs are to be optimized, purge each VDU BEFORE issuing the
       command to optimize the VDUs.  The DCF2 must be running for the purge
       operation and must NOT be running for the recompression or optimize
       operation.


  DCF2PAKRCommandLineParameters

  ΓöîΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö¼ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÉ
  ΓöéCommand   ΓöéParameter           ΓöéFunction                                Γöé
  Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
  ΓöéDCF2PAKR  Γöé/P /V:X             ΓöéPurges VDU X, where "X" is the VDU's    Γöé
  Γöé          Γöé                    Γöédrive letter.  The DCF2 must be running.Γöé
  Γö£ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö╝ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöñ
  ΓöéDCF2PAKR  Γöé/O /V:X             ΓöéOptimizes VDU X, where "X" is the VDU's Γöé
  Γöé          Γöé                    Γöédrive letter.  Before "optimizing",     Γöé
  Γöé          Γöé                    Γöéshutdown the DCF2.                      Γöé
  ΓööΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓö┤ΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÇΓöÿ


ΓòÉΓòÉΓòÉ 9.3. DCF/2 OS/2 System Shutdown Parameters (SHUTDOWN.EXE) ΓòÉΓòÉΓòÉ

The SHUTDOWN.EXE includes several optional parameters which you execute from
either an OS/2 command processor or you can set using the DCF/2 OS/2 System
Shutdown icon's Settings Notebook on your Desktop.  These are:

     Parameter      Function
     /i             Interactive shutdown.  Prompts you to answer yes/no to
                    cancel shutdown.
     /n             No system shutdown.  Shuts down the DCF2ACP only.
     /t             "Thinkpad" or the like.  This optional parameter doesn't
                    kill processes, but shuts down the DCF2ACP.EXE and system.
     /s             Single click shutdown.  On some systems, this may result in
                    an infinite shutdown loop!
     /d:            Default time in seconds for the Shutdown Countdown.  The
                    default is 10 seconds.  Increase this number if your do not
                    reach the final C-A-D box at shutdown.
     /w:            Smallest Process ID number (detached processes) in a range
                    of PIDs to "kill" at shutdown.
     /W:            Largest Process ID number (detached processed) in a range
                    of PIDs to "kill" at shutdown.


ΓòÉΓòÉΓòÉ 9.4. DCF/2 Monitor Parameters (DCF2MON.EXE) ΓòÉΓòÉΓòÉ

Like the SHUTDOWN.EXE program, DCF2MON.EXE 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:

     Parameter                            Function
     /l:X                                 VDU Drive letter for this LED icon.
     /x: followed by a decimal value.     Designates the x coordinate location
                                          of the LED icon on your Desktop.
     /y: followed by a decimal value.     Designates the y coordinate location
                                          of the LED icon on your Desktop.
     /t: followed by time in seconds.     Establishes the refresh frequency for
                                          the LED icon.  Increase this if you
                                          feel the monitor refreshes are
                                          loading your system.  (Applies to
                                          certain video adaptors.)


ΓòÉΓòÉΓòÉ 9.5. Converting DCF/2 Version 1.1a VDU's to Version 1.1b ΓòÉΓòÉΓòÉ

Note:  Before you can use DCF/2 Version 1.1a VDU's with Version 1.1b, you must
       follow the procedure outlined below to "convert" them.

  1. Backup your 1.1a VDU before installing the DCF/2 1.1b.

  2. Do not use the "Update/Register" option on the installation menu.  Do a
     full install according to the following steps:

     a. REM out all DCF/2 1.1a statements in your CONFIG.SYS file.
     b. Rename any existing DCF/2 VDUs to names other than DCF2_X.VDU, (e.g.,
        DCF2_X.11A); so that the install program does not delete it.
     c. Reboot your computer system.
     d. Install the DCF/2 Version 1.1b.
     e. Reboot your computer system (the install program will do this for
        your).

  3. Let the DCF/2 startup normally.

  4. Go to an OS/2 command prompt and change to the DCF/2 program directory.

  5. Use a SET statement to point to your version 1.1a VDU:  SET
     DCF2_VDU_X=DCF2_X.11a.

  6. Stop the DCF/2 using the command, DCF2 /A:SHUTDOWN.

  7. Use the DCF2PAKR program to decompress and then recompress the data in the
     VDU:   Type DCF2 /O /V:X, where "X" is the VDU's drive letter.

  8. Your Version 1.1a VDU is now reformatted for Version 1.1b usage.

 Note:  The conversion takes approximately 1 minute per 1K chunks of data.  Do
        not interrupt interrupt the DCF2PAKR program or the VDU will be lost.


ΓòÉΓòÉΓòÉ 9.6. 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-bassed 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('Nane',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 9.7. Hints for Running Your Applications from a VDU 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 testers, based on
their experiences with some of the more finicky applications.

AmiPro 3.0a

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.

FaxWorks

The FaxWorks device driver loads before the DCF/2 starts up.  As a result, if
it is on a VDU, the device is not found.  Workaround:  Load FaxWorks FMD.SYS
from 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 9.8. Tips & Techniques ΓòÉΓòÉΓòÉ

The following tips and techniques for using the DCF/2 were contributed by DCF/2
beta testers.

Maintenance Partition

While you may never need one, should "disaster strike" (DCF/2 or otherwise),
you won't regret time you spent creating a small -- 3MB, for example --
maintenance partition. Include on your maintenance partition a small editor
should you need it 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 CHKDSK exercises on the "normal" partition can be performed.

If you have access to CompuServe, you may want to download BOOTOS.ZIP from
OS2USER, Library 17 (also EWS).  The file is intended for those in need of a
bit of assistance when creating a maintenance partition.

Devices that Load in the CONFIG.SYS

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

Read/Write or Magneto Optical Drives

In the event of an improper shutdown (loss of power, trap, hang, etc.) for the
case in which the VDU host is an 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 9.9. 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."


Case 1:  HPFS Partitions Only

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  ΓöéN/A       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 10. Glossary of Terms ΓòÉΓòÉΓòÉ

The glossary provides definitions for commonly used terms.

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.

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.

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.

Host Drive

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

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.

DCF/2 VDU Control Process (DCF2VCP)

The DCF2VCP manages the virtual disk units you create using the controller
(DCF2ACP).

DCF/2 Space Manager

One of the most important functions of the VDU Control Process (DCF2VCP) is
space management for each of your VDUs.  DCF2VCP monitors the amount of space
available on each VDU's host drive and prevents the VDU from running out
physical space.

"Dirty"

The term "dirty" is used to describe the state of a physical or virtual drive
when the drive was shutdown by a means other than running the DCF/2 shutdown
program.

Typically, this happens if you switch off the computer without running shutdown
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.