Freelog Special Edition 1: Linux/CD1.iso/dosutils/fips20/fips.doc

Text File | 1998-05-09 | 24KB | 526 lines

                  Welcome to FIPS
    The First nondestructive Interactive Partition Splitting program

                Version 2.0
                   May 11, 1998

              Copyright 1993-98 Arno Schaefer
        Parts of the code Copyright 1997/98 Gordon Chaffee


0.  What you need to use FIPS
1.  Introduction
2.  What FIPS does
3.  Safety
4.  Restrictions
5.  Before you start
6.  Use with a multitasking OS
7.  Using FIPS
8.  After splitting the partition
9.  Commandline Switches
10. Troubleshooting
11. Credits


In file SPECIAL.DOC:

S1. Use with Stacker/SuperStor/Doublespace etc.
S2. Use with OS/2
S3. Use with OnTrack Disk Manager and similar drivers


FIPS is a program designed to split an existing DOS partition without deleting
the data on it.

FIPS is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

FIPS is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with FIPS; see the file COPYING.  If not, write to
the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.

Report problems and direct all questions to:

    [e-mail]


0. What you need to use FIPS

You need a defragmentation program in order to move all data to the beginning
of the hard disk. FIPS will only split your partition if you have enough free
space at the end. Windows 95 and later MS-DOS versions contain DEFRAG, which
is suitable for this purpose. Other suitable programs are Norton Speedisk
PCTools' Compress, DISKOPT in Novell DOS 7, or the shareware programs ORG,
DOG or SAFPAK (available by anonymous FTP from any SimTel mirror in the
diskutil directory). I did not test these however, so don't blame me if they
don't work for you.

You may also want to use a program like Norton Disk Doctor (or 'scandisk'
in DOS 6.*/Windows 95) to check your harddisk before and after using FIPS.

FIPS was developed under DOS 5.0. It should work fine with anything above
3.0, perhaps even with 2.0. However it will not be of much use with older
DOS versions, since the large partition sizes are only available since DOS 4.
It has been reported to work with DOS 6.0 and 6.2 and Novell DOS 7. I have
also received reports about successful use with Windows 95 partitions. Note
that the long filenames are no problem for FIPS, because it works on a
lower level where directory structure is of no concern. It is probably
sensible to boot from a DOS disk before using FIPS in such a setup (see 6.)



1. Introduction

The program was inspired by the Linux Project. When installing Linux on a
PC that was used for DOS / Windows, many people want to retain a smaller
partition for their DOS software. However, since most Harddisks contain
only one large partition, you would normally be required to do a complete
backup, erase the partition and build two (or more) new partitions. Then you
would restore the backup to one of the new partitions. On today's systems
with hard disk capacities of usually 500MB or more, a complete backup becomes
practically infeasible without large media like streamer tapes once the
drive has filled up to some considerable fraction. Even though many people
backup their most valuable date (a practice which I would highly recommend
in any case), the process of reinstalling all the software packages takes
many hours or even days.

FIPS was written to remedy this problem. You can now split a partition
without losing any data, provided there is enough free space for the new
partition at the end of the old one.


2. What FIPS does

FIPS reduces the size of a partition by changing some values in the
partition table and boot sector. It does not change the formatting of
the partition, especially not the cluster size and the size of the file
allocation table (FAT). Therefore the reduced partition will have a FAT
that is in part unused, but this is not a problem for DOS.

From the free space that is won by this, FIPS creates a new _primary_ DOS
partition.

If you want to use the new partition under a different OS (e.g. Linux), use
its supplied fdisk program to make any necessary changes (refer to the OS
manuals).

If you want to use the new partition under DOS/Windows, you can use it as
it is (after formatting!), but be aware of the following:

According to the official references, DOS can only have one primary
partition. All DOS versions (at least from v5.0 on) will happily work with
multiple primary partitions, but this is an 'undocumented feature'. If
you want to follow the official rules, you can delete the new partition with
fdisk and create an extended partition in its place.

There are reasons for having multiple primary partitions, among them the
possibility to boot from different partitions by changing the active par-
tition with fdisk.

Known problems with multiple primary partitions are:

- If you accidentally delete one primary partition with fdisk, you can not
  easily recreate it, since fdisk will refuse to. There may be other fdisk
  programs around that work, and if all else fails you can boot from a
  Linux boot disk to run Linux' fdisk, but it is always a hassle.

- There exist some software packages that work with the partition table and
  which may be confused by multiple primary partitions. Among them was SFS,
  the 'Secure file system' by Peter Gutmann. I think Peter has made a change
  to his program to accept some unusual configuration, but there may exist
  other software packages that will have problems.


3. Safety

FIPS was specifically designed to provide a maximum of safety. On startup
it checks the Partition Table, Boot Sector and FAT for any inconsistencies.
If it finds anything suspicious, it will tell you so. If there are errors,
FIPS will not proceed.
You have the possibility to write backup copies of your root and boot sector
to a floppy disk before proceeding. If something goes wrong, you may restore
these with the program 'restorrb.exe' (see section 5). I strongly recommend
making use of this feature. It will also enable you to reverse the partition
split afterwards, so it might be a good idea to save the root/boot sector
image in a safe place.
FIPS checks for free space on the partition and will let you choose the
new start cylinder accordingly.
After having calculated the new partition table and boot sector, FIPS will
check everything again, so that possible bugs in the calculation may be
detected. Only if everything is ok, FIPS will ask for permission to write
the new root and boot sector.


4. Restrictions

FIPS will only work with Hard Disk BIOSes that use interrupt 13h for low
level harddisk access. This is true for almost all PCs. I have received
a report that an older Adaptec SCSI controller had a software driver
that worked on a higher level. In this case you can only hope to get a
new driver from Adaptec. This is no problem any more for all newer
Adaptecs (I personally use one).

FIPS will only work on disks with a sector size of 512 bytes.
It seems that DOS is prepared to deal with different sector sizes, but
so far I have never seen this.

FIPS will not split partitions with 12 bit FATs (you would not want to split
partitions with less than 10 MB, would you?).

FIPS will only split DOS partitions. Partition table and boot sector must
conform to the MSDOS 3.0+ conventions. This is marked by the system
indicator byte in the partition table, it must have the value 4 (16 bit
sector number) or 6 (32 bit sector number).
It will especially *not* split Linux partitions.
NEW: Windows 95 FAT32 partitions are now also supported.

FIPS does not work on extended DOS partitions.

FIPS will not work if you already have four partitions, since it needs one
free partition entry.

FIPS will not reduce the original partition to a size with less than 4085
clusters, because this would imply rewriting the 16 bit FAT to a 12 bit FAT.


5. Before you start

Run CHKDSK or SCANDISK on the partition you want to split.
If you have Norton Disk Doctor or something similar, you may use it alter-
natively. Make sure there remain no 'dead' clusters on the disk.

Prepare a bootable floppy disk in drive A:. Under DOS this is usually done
by giving the command 'sys a:' or 'format a:/s'. Under Windows NT or OS/2
this may be different, if in doubt check your manual or boot from a boot
disk from a DOS PC.

Copy the FIPS files RESTORRB.EXE, FIPS.EXE and ERRORS.TXT to this disk.

Test booting from the prepared floppy disk. Read you manual or ask a local
guru if you can't boot from floppy disk or if you can not access your hard
disk after booting (test this by giving the command 'dir c:', you should
see your hard disk's root directory). If all else fails, try using FIPS
after booting normally from the hard disk (a bit more risky, but sometimes
the last resort).

When you start FIPS (later!), you will be given the opportunity to write
backup copies of your root and boot sector to a file on drive A: called
ROOTBOOT.00x (where x stands for a digit from 0 to 9). If anything goes wrong
while using FIPS, you can restore the original configuration by booting from
the floppy and running RESTORRB. Please note: if you use FIPS more than once
(this is normally not necessary, but it may happen), more than one ROOTBOOT
file is written to the floppy disk. RESTORRB lets you choose which configu-
ration file to restore. The file RESTORRB.000 contains your original confi-
guration. Try not to confuse the versions.

You will need this backup file (ROOTBOOT.00x) if you want to undo the
partition split later.

But before starting FIPS you _must_ now defragment your Harddisk. All of the
space that will be used for the new partition must be free. Be aware that the
Windows Swapfile will not be moved by most defragmentation programs. You must
uninstall it (in the 386enhanced part of the Windows Control Panel) and rein-
stall it after using FIPS.
If you use IMAGE or MIRROR, the last sector of the hard disk contains a
hidden system file with a pointer to your mirror files. You _must_ delete this
file before using FIPS (it will be recreated the next time you run mirror).
Do 'attrib -r -s -h image.idx' or 'attrib -r -s -h mirorsav.fil' in the root
directory, then delete the file.
If FIPS does not offer as much disk space for creation of the new partition
as you would expect it to have, this may mean that

a. You still have too much data in the remaining partition. Consider making
   the new partition smaller or deleting some of the data.

b. There are hidden files in the space of the new partition that have not
   been moved by the defragmentation program. You can find the hidden files
   on the disk by typeing the command 'dir /a:h /s' (and 'dir /a:s /s' for
   the system files). Make sure to which program they belong. If a file is
   a swap file of some program (e.g. NDOS) it is possible that it can be
   safely deleted (and will be recreated automatically later when the need
   arises). See your manual for details.

   If the file belongs to some sort of copy protection, you must uninstall
   the program to which it belongs and reinstall it after repartitioning.

   I can't give you more aid in this - if you really can't figure out what
   to do, contact me directly.

Attention! Do _not_ try to move DOS' hidden system files (ibmbio.com &
ibmdos.com or something similar). You may end up with a hard disk that
will not boot any more. Since these files are already in the first sectors
of the partition, it is not necessary to move them. In DOS 5.0 and later,
at least one of the system files _may_ be moved, but it is nevertheless a
good idea to leave it alone.

When you have run FIPS, you must reboot, so make sure to disable any
programs in the config.sys and autoexec.bat that write to the disk, in
particular mirror or image. Consider temporarily renaming these files.

Be aware that the location of your DOS partitions in the partition table may
change after using FIPS. If you use the new partition under DOS _and_ you
have an extended partition and/or two drives, this means that the names of
the partitions may change (e.g. D: may become E:). I have taken care that C:
always remains C:, so that you will still be able to boot.

Also if you have a CD-ROM, it will in most cases change its drive letter.
If you use the /L switch to explicitly specify the drive letter in the call
to MSCDEX in the autoexec.bat file, you might have to change it accordingly.
If you don't use the /L switch, MSCDEX will automatically choose the first
free letter, so that you do not need to change anything.

Apropos drive letters: DOS uses the following order to assign them:
1. The first primary partition on each drive
2. The volumes inside the extended partitions on all drives
3. The remaining primary partitions on all drives

Example:

C: first primary partition on first HD
D: first primary partition on second HD
E: first volume in extended partition on first HD
F: second volume in extended partition on first HD
G: first volume in extended partition on second HD
H: second primary partition on second HD
I: CD ROM

I am not aware of an easy way to change this scheme. In particular you
can not assign an arbitrary drive letter to a partition. You can however
influence the ordering by changing a primary partition into an extended one.

For Linux users:
The possible change of the location of the DOS paritition in the partition
table also means that the device number of the DOS partition under Linux may
change (e.g. /dev/hda3 may become /dev/hda1). Any existing Linux partitions
will not change, so that you will have no trouble booting. You just need to
edit your /etc/fstab file if you mount your DOS partition on bootup.


6. Use with a multitasking OS

You should not use FIPS in multitasking environments like OS/2, Desqview,
Windows, Novell Task Manager or the Linux DOS Emulator. These systems might
still write to the disk after FIPS has changed the hard disk structure,
which may result in corrupting the disk. This is not necessarily so, I'd
suppose that in most cases it would work nevertheless. But since safety is my
first concern with FIPS, I would recommend booting from a DOS boot disk and
then running FIPS, that should be safe.
In version 1.0 I added some code by Dave McCaldon to detect Windows and
Desqview (thanks, Dave!). OS/2 and Novell Task Manager are not yet detected.
I had to remove the code for detecting the Linux DOS emulator because it
caused a hangup on many machines.


7. Using FIPS

If you have prepared a bootable floppy disk as described in section 5,
boot from it now.

Important! Make sure not to have a disk cache program like Smartdrive
running. It has been reported that in some cases the changes FIPS made
were only written to the disk in part, which resulted in hard disk
corruption later. I think this may be caused by the use of Smartdrive,
which in the default configuration delays the disk writes for some seconds.
If you reboot too fast, some of the changes may be lost.

You start FIPS by typing FIPS at the DOS prompt, followed by <ENTER>.
You may exit from the program at any time by pressing <CTRL-C>.

FIPS will first try to detect under which OS it is running. If it is
Windows or Desqview, it will complain and tell you to boot from a floppy
disk. You can proceed nevertheless, but this is at your own risk (see
section 8).

Then FIPS will detect your hard disks, if you have more than one, it will
ask you which one you want to work on.
In previous releases, FIPS failed to detect the correct number of hard disks
with some BIOSes (esp. in Gateway Pentium machines). I hope to have corrected
this. If FIPS fails to detect the correct number of disks, please let me
know. In the meantime you may use the '-n' switch to select the drive
by hand (see below).

FIPS then reads the root sector of the hard disk and displays the partition
table.

Example:

     |        |     Start      |      |      End       | Start  |Number of|
Part.|bootable|Head Cyl. Sector|System|Head Cyl. Sector| Sector |Sectors  |  MB
-----+--------+----------------+------+----------------+--------+---------+----
1    |    yes |   0  148      1|   83h|  15  295     63|  149184|   149184|  72
2    |     no |   1    0      1|   06h|  15  139     63|      63|   141057|  68
3    |     no |   0  140      1|   06h|  15  147     63|  141120|     8064|   3
4    |     no |   0    0      0|   00h|   0    0      0|       0|        0|   0


If you don't know what to make of this, don't worry too much. You may just use
the number of Megabytes to identify your partitions.

The root sector is then checked for errors.

If you have more than one partition on the disk, you will be asked which one
you want to split.

The boot sector of the chosen partition is read and some information is dis-
played.

Example:

Bytes per sector: 512
Sectors per cluster: 8
Reserved sectors: 1
Number of FATs: 2
Number of rootdirectory entries: 512
Number of sectors (short): 0
Media descriptor byte: f8h
Sectors per FAT: 145
Sectors per track: 63
Drive heads: 16
Hidden sectors: 63
Number of sectors (long): 141057
Physical drive number: 80h
Signature: 29h


FIPS checks if this information is consistent with the partition table and
tries to detect other errors.

It then verifies if the two copies of the FAT are identical, if they are not,
FIPS will exit with an error message.

If everything checks out ok, FIPS now looks for free space at the end of
the partition. The new partition must have at least one cylinder, so if
the last cylinder is not free, you have no chance of splitting the
partition: FIPS will exit with an error message. Probably you forgot
to remove a mirror or image file (see above).

You must now enter on which cylinder the new partition should start.
Use the cursor keys right/left to increase or decrease the cylinder
count. The size of the remaining partition and the new partition are
displayed in the process, so you will have no trouble choosing the
right cylinder. With cursor up/down you can change the count in steps
of 10. When ready, press enter to continue.

FIPS will check again if the space for the new partition is empty -
this is an additional security measure and should never show an error,
since the free space was already determined before.

After this, FIPS will calculate the changes to the root sector, check the
changes and display the new partition table. You may now choose to reedit the
partition table (this will return you to the point where you select the par-
tition) or to continue. If you type 'c', FIPS will calculate the changed
boot sector, check it again and prompt you if you want to proceed. If you type
'y' then, FIPS will write the changes to the disk and exit.


8. After splitting the partition

Make sure that the changes have been written to the disk. If you used
a disk cache like Smartdrive (despite my explicit recommendation not
to use it :-), wait for some seconds so that the cache is flushed to disk.

Your new partition will be recognized by DOS after you rebooted. DO NOT
WRITE ANYTHING TO THE DISK BEFORE REBOOTING. After rebooting, use CHKDSK
or Norton Disk Doctor to make sure your old (now smaller) partition is ok.

There have been cases where the changes made by FIPS were not correctly
written. To make sure that this is not the case, run FIPS again with the
-t (test mode) switch after rebooting. Select the drive and partition that
you were splitting. If FIPS displays no error until the cylinder selection
dialogue, there is no problem and you can stop the program with CTRL-C.
Otherwise you should undo the changes with 'restorrb' and contact me by
email.

If you don't find any errors, you may now reboot with your normal config.sys
and autoexec.bat. Start some programs and make sure you can still read your
data.

If you want to use your new partition under DOS, you must format it. If you
have multiple partitions, make sure to format the right one, the drive names
may have changed!
If you want to use the partition under Linux, you may now change the system
indicator byte with Linux' fdisk, then use MKFS.

If you want to split the new partition again in two smaller ones, you must
first format it under DOS, otherwise FIPS will complain.


9. Commandline Switches

Here is the explanation of FIPS' commandline switches. If you prefer the DOS
style, you may use '/' instead of '-' as the switch character. The switches
may be arbitrarily combined. Type 'FIPS -help' to get a list of the switches.
Here is a more detailed explanation:

-t or -test : test mode (no writes to disk)

This doesn't need much explanation.

-d or -debug : debug mode

In this mode, a complete transcript of your session along with some additio-
nal information is written to the file FIPSINFO.DBG in the current directory.
You can send this file to me in case of trouble (see below).

-h or -help or -? : help page

A short summary of the switches

-n<num>   : select drive <num>

Preselect the drive number with this switch. Valid numbers are 128 to 255.
This may also be used to override the automatic drive detection - if for any
reason the drive is not found by FIPS, you may try this switch.


10. Troubleshooting

FIPS is still somewhat experimental, although it has been used by many
people successfully and without serious problems.
When in doubt I usually decided to stay safe and display error messages
when encountering suspicious configurations. Some of the minor errors may
be overridden.

Please make sure you have read this doc carefully and also look in the file
FIPS.FAQ that covers some frequently asked questions.

If you can't resolve a problem yourself, or have a configuration not sup-
ported by FIPS, or if you suspect a bug in FIPS, make a transcript of your
session using the -d switch and send the full FIPSINFO.DBG file along with a
short comment to [e-mail]. Possibly your
problem has already been solved.


11. Credits

FIPS is based on the procedure described by Drew Eckhardt in Linux digest132.
Most of what I know about Harddisk structures comes from the excellent german
book 'Scheibenkleister II' by Claus Brod and Anton Stepper. It is for the
Atari ST, but much of it applies to PCs also.
Information on the Harddisk Interrupts was drawn from Ralf Brown's Interrupt
List. Thanks to Hamish Coleman for some useful info and to Paul Smith for
his good suggestions. Gunnar Hilmarsson suggested the procedure for stacked
drives, and Miguel Alvarez helped me improve the partition ordering. Chetan
Patil, Rand Phares and Eric Jung pointed me at bugs in the program and
documentation. Stefan Andreasen provided important informations about OS/2.
Keith Crews suggested some additions to the documentation concerning the
preparation of the boot disk and new features of DOS 6.x. Dave McCaldon
wrote the code for detecting the OS FIPS is running under. Scott Ellentuch
and Billy Patton provided info about OnTrack Disk Manager.
A very valuable piece of info on EIDE drives and address translation is the
Linux EIDE-Mini-HOWTO by Patrick LoPresti.
Many thanks to Gordon Chaffee for the FAT32 support.
Thanks to all others who sent me feedback and suggestions. FIPS would not be
the same program without the innumerable emails I received.


Arno Schaefer
[e-mail]