=== DISCLAIMER ===
I allow you to use all software in this package freely under the condition
that I am in no way responsible for any damage or loss you may suffer.
>> You should be aware of the fact that FAT32.IFS might <<
>> damage the data stored on your hard disks. <<
NEW: FAT32 support now can be made possible by using a filter device instead
of a modified OS2DASD.DMD. By installing this filter in a READONLY mode,
your harddisk can be protected against corruption.
If you cannot agree to these conditions, you should NOT use FAT32.IFS !
I CANNOT guarantee that FAT32.IFS will work for you. However I've done
my best to test the program and I can only say that It works for me.
Certified daddy (by my kids)
FILES IN THIS VERSION
FAT32.TXT This file.
FAT32.IFS The actual IFS.
CACHEF32.EXE The cache helper program.
UFAT32.DLL The module needed to run CHKDSK on FAT32 partition.
F32STAT.EXE A program to change the DIRTY flag of FAT32 partitions.
MONITOR.EXE A program to monitor what FAT32.IFS is doing.
PARTFILT.FLT A general partition filter device that allows FAT32
partitions to be recoqnized by OS/2.
OS2DASD.DMD A modified version of OS2DASD.DMD that is an
alternative for using PARTFILT.FLT. This modified
driver also allows FAT32 partitions to be recoqnized
PLEASE NOTE: that this driver is NOT at the latest
level and will probably NOT support the latest
features like removable disks etc.
DISKINFO.EXE A diagnose program that will scan for and show
This version of FAT32.IFS has the following limitations:
- It only supports non-removable harddisks.
- It only supports disks with a sector size of 512 bytes. (Are there others?)
- There is NO support for Extended attributes.
- You cannot BOOT from a FAT32 partition.
- You cannot place the SWAPPER.DAT on a FAT32 partition.
- CHKDSK can diagnose a disk, but will only FIX lost clusters and an
incorrect free space count. For all other errors, you'll need to run
Windows95 and start scandisk to fix the problem.
Note: CHKDSK will always convert lost clusters to files and NEVER to
directories. if you want that, use SCANDISK.
- The FORMAT, RECOVER and SYS commands are not supported.
- Only last access date (and not last access time) is maintained by
FAT32.IFS. This is similiar to Win95 (OSR2).
- Long filenames are not supported in DOS and Win-OS/2 sessions,
they use only the shortnames.
There are more restrictions.
Please see 'LONG FILENAMES IN OS/2 AND DOS SESSIONS' later is this file.
- A maximum of 235 different files can be open at the simultaniously.
The number of times a single file is opened does not matter. So if a
specific file is opened more than once, it only counts as one file.
HOW TO INSTALL
Copy the following files to your \OS2 directory:
Copy the following file to your \OS2\DLL directory:
Copy the following file to your \OS2\BOOT directory:
Do NOT REPLACE your currentT OS2DASD.DMD with the version in the archive.
See the remark below about OS/2 and FAT32.
Make the following changes to the CONFIG.SYS:
IFS=x:\OS2\FAT32.IFS [options, see below]
(Install this one AFTER IFS=HPFS.IFS)
CALL=x:\OS2\CACHEF32.EXE [options, see below]
^^^^-> Make shure this is a CALL and NOT a RUN.
BASEDEV=PARTFILT.FLT /P 0B [/W]
(The /W should not be specified if you do not want write access)
(Install this one as FIRST BASEDEV !)
(x should be replaced by your boot drive.)
FAT32.IFS is the actual Installable File Systems driver.
The following options are supported:
/Q Quit, not messages.
/CACHE:nnnn specifies the cache size in kilobytes. If omitted the default
cache size is 1024KB. Maximum cache size is 2048KB.
Cache memory is allocated as FIXED memory, so if you have less
than 16MB I suggest you set this option to 512KB or less.
/MONITOR Set monitor ON by default. If omitted monitor is OFF. See
MONITOR.EXE for more information.
/RASECTORS:n Read Ahead Sectors.
Specifies the minimum number of sectors to be read per read
action and placed in the cache.
If omitted the default differs per volume and equals the
number of sectors per cluster times 2.
The maximum treshold value used is the number of sectors per
cluster times 4.
You should note that the actual sector IO per read action is
NOT determined by an application, but by the IFS. For FAT access
single sector reads are done. For Directory and Files IO reads
are done on a cluster base. By setting the RASECTORS you can
define the minimum number of sectors the IFS will read from disk
and place in the cache.
CACHEF32.EXE is a helper program with the following functions:
- Check DISK state on boot, run CHKDSK if needed.
- Start the LAZY WRITE daemon.
- Set CACHE and READ-AHEAD parameters.
- Set Longname behaviour.
When run in the foreground and CACHF32 is already running, it displays
the CACHE parameters and allows you to modify the values. If no other
copy of CACHEF32 is running, it detaches a background copy.
When run in the background (detached), CACHEF32 will act as lazywrite daemon.
CACHEF32.EXE supports the following options:
/? Shows help.
/Q Terminates CACHEF32. CacheF32 will be unloaded from memory, lazy
writing will stop. (Performance will degrade).
/D:nn Sets the DISKIDLE value. See OS/2 online help on CACHE.
/B:nn Sets the BUFFERIDLE value. See OS/2 online help on CACHE.
/M:nn Sets the MAXAGE value. See OS/2 online help on CACHE.
/R:d:,n Set RASECTORS for drive d: to n.
/FS Use short names internally.
/FL Use long names internally (default).
(see LONG FILENAMES IN OS/2 AND DOS SESSIONS below)
Before anything else: PARTFILT is based on the excelent work of
Deon van der Westhuysen. I only made minor modification to it. The source
code is available under GPL conditions. Please send me a mail if you want
the sources. My current homepage lacks space to store the sources.
PARTFILT.FLT is a BASEDEV FILTER device that as able to presents (fakes)
partition types that are normally unsupported by OS/2 in such a way to OS/2
that IFS's can be loaded on these partitions. Such virtualized partition
will always be mounted after the non-virualized partitions.
Currently (as far as I know) the filter can be used for two IFS's:
This one, FAT32.IFS and the Linux IFS.
Beside that, PARTFILT.FLT can be used for other purposes such as making
not-visible partitions visible or using multiple primary partitions.
PARTFILT.FLT supports the following options:
/Q Load quietly
/W Enables Writing to the faked partitions. Without this option
the faked partitions are read-only.
/A This option does two things:
- Disables OS/2 to access all partitions, but:
- Virtualizes (or fakes) all known partitions.
Known partitions are the normal FAT partitions,
IFS (=mainly HPFS) partitions and the partitions specified
with the /P option.
All primary partitions of known types are also virtualized,
and will be accessable from OS/2.
This option must be used in conjunction with the /M option.
WARNING: Incorrect usage of this option could make your system
This option specifies which of the with /A vitualized partitions
should be made available for OS/2 and in what order they should
be mounted. (The 1st partition loaded get the C: drive, the 2nd the
D: drive, and so on).
You should make sure that you OS/2 partition gets the same drive
letter as normal or your system will not boot properly.
Also, without the /W options, OS/2 will not work since it cannot
write to its bootdisk.
The mountlist should contain partition sequence numbers seperated
by comma's. Partition sequence numbers are shown by DISKINFO.EXE.
See diskinfo.exe for more information.
/P <partition types to fake>
This is option is used to tell PARTFILT which partition type are to
be faked. You should NOT use partition types already supported by
OS/2 since this would result in a single partition being mounted
two times. The list should consist of partition type numbers (in
hexadecimal), separated by comma's.
The partition type number are as follows:
01 FAT12 (supported by OS/2)
04 FAT16 (supported by OS/2)
06 HUGE (supported by OS/2)
07 IFS (supported by OS/2)
10 Hidden partition (bits OR'd with partition type)
To make PARTFILT.FLT fake a FAT32 partition the /P option should be /P 0B.
To make PARTFILT.FLT fake a LINUX partition the /P option should be /P 83.
To fake both specify /P 0B,83.
CHKDSK & UFAT32.DLL
The UFAT32.DLL is called by CHKDSK whenever the CHKDSK command is issued
for a FAT32 drive. UFAT32.DLL currently only supports CHKDSK.
For CHKDSK the following options are implemented:
/F Fixes problems (Currently UFAT32.DLL only fixes lost clusters,
and an incorrect free space count.)
/C Causes lost clusters to be automatically converted to files if the
drive was in an inconsistent state at boot (No questions asked).
/V Causes CHKDSK to show details on all files checked.
The CHKDSK process does the following checks:
- Compares all copies of the FATs;
- Checks for each file the file allocation;
- Checks per file or directory the VFAT long filename;
- Checks for, and if /F is specified, repairs lost clusters.
- Checks for, and if /F is specified, repairs cross-linked files.
- Checks free space, and if /F is specified, corrects an incorrect setting.
F32STAT can be used to query the clean shutdown state of a FAT32 drive.
It also allows you to alter the clean shutdown state. You could use this
feature if FAT32.IFS blocks access to the disk because it is dirty on boot,
and CHKDSK could not solve the problem.
The syntax is:
F32STAT drive: [options]
The following options exist:
/CLEAN - Inform FAT32.IFS that the disk was clean on boot and may be used.
The disk itself will be marked as clean on a succesfull shutdown.
(The internal dirty flag FAT32.IFS uses will be cleared.)
/FCLEAN - Inform FAT32.IFS that the disk was clean on boot and may be used.
The disk itself will also be marked as clean at that moment.
(The internal dirty flag FAT32.IFS uses will be cleared, but the
marking on disk will also be set ok.)
/DIRTY - Inform FAT32.IFS to set its internal dirty flag, and mark the drive
dirty on disk. On shutdown the drive will be left dirty, so when
booting Windows 95 (OSR2) SCANDISK will be fired.
Monitor will show (most) FAT32 actions on screen. This program is intended
for troubleshooting. Using MONITOR will degrade performance since FAT32 must
send monitoring information to an internal buffer. This internal buffer is
only 4096 bytes large, so if monitoring is on, but MONITOR does not run,
logging information is lost.
If the /MONITOR command is not specified in the config.sys after the IFS=
statement monitoring is OFF by default, but starting MONITOR once will
Only one option is available:
MONITOR off - This will tell the IFS that no monitoring information has to
be stored (This will improve performance).
When run with no options, diskinfo will scan and show all partitions.
The following options are available:
/V - Verbose mode. Show more info, specifically on FAT32 partition.
/B - Show the boot sector of FAT32 partition. Only if /V is only specified.
/P - Allows you to specify a list of partition types that should also get
a partition sequence number. See PARTFILT for more information.
An example of output from DISKINFO (without parameters):
There are 2 disks
=== Scanning physical disk 1.===
0:P__ 06 HUGE Start:H: 1 C: 0 S: 1 End:H: 127 C: 258 S: 63
-:PA_ 0A BOOTMANAGER Start:H: 0 C: 523 S: 1 End:H: 127 C: 523 S: 63
1:LB_ 06 HUGE Start:H: 1 C: 259 S: 1 End:H: 127 C: 387 S: 63
2:LB_ 07 IFS Start:H: 1 C: 388 S: 1 End:H: 127 C: 522 S: 63
=== Scanning physical disk 2.===
3:P_H 11 FAT12 Start:H: 1 C: 0 S: 1 End:H: 127 C: 0 S: 63
-:L__ 0B FAT32 Start:H: 1 C: 1 S: 1 End:H: 127 C: 524 S: 63
(Seq#:Primary/Logical, Active/Bootable, Hidden?, Partition type (hex & desc))
The partition sequence number can be used to determine how the /M parameter
for PARTFILT.FLT should be specified. When using DISKINFO for this purpose it
is best NOT to have PARTFILT installed since the faked partitions will also
be shown by DISKINFO.
When PARTFILT is not installed, and OS/2 is booted, a C:, D: and E: drive
will be available for partitions sequence numbers 0, 1 and 2.
Please note that the partition with seq# 3 is a hidden partition and OS/2 will
by default not assign any drive letter to it.
The use PARTFILT with the /A and /M options the options should be:
BASEDEV=PARTFILT.FLT /W /A /M 0,1,2
To get the same result as without the filter. While:
BASEDEV=PARTFILT.FLT /W /A /M 1,0,2
will swap the C: and D: drive letters.
Should I have started DISKINFO with the /P 0B parameter, the FAT32 partition
would have got sequence number 4 assigned.
MAKING OS/2 RECOQNIZE FAT32 PARTITIONS.
OS/2 by itself does not recoqnize FAT32 partitions. This means that
installing the IFS is useless if we can't make OS/2 recoqnize them.
Currently there are two ways to achieve that.
- Use PARTFILT.FLT to fake FAT32 partition; (this is advised)
- Use the modified version of OS2DASD.DMD.
The version of OS2DASD.DMD supplied in this package is a modified version
of this driver and is NOT at the latest level. This means that it
is possible that some of the latest features in the IBM supplied driver may
not be supported. Also, when installing new fixpacks, you should make sure
that this version of OS2DASD.DMD is not replaced.
Also, when using this driver, FAT32 partitions COULD end up having a drive
letter assign before the OS/2 partition, shifting the assigned drive letters
for all next partitions up and thus making OS/2 unbootable.
This version of OS2DASD.DMD has extra support for partition type 11 (hex B).
Partition type 12 (hex C), FAT32 through INT13 is NOT supported by this
IBM Is working on a version of OS2DASD.DMD that should recoqnize
Generally, it is not advised to use this version of OS2DASD.DMD, but to
use the PARTFILT.FLT.
LONG FILENAMES IN OS/2 AND DOS SESSIONS
In the initial release long file names where only shown in OS/2 sessions, but
in DOS sessions, the short filename equivalent was shown.
This could however lead to big problems. An example:
In in an OS/2 session directory \DevStudio was current, from a DOS session
the directory \DEVSTU~1 could be removed since OS/2 didn't know that
DevStudio and DEVSTU~1 were infact the same directories.
The same problem could occur when opening files in both OS/2 and DOS.
No proper multiuser handle would take place since OS/2 doesn't know that
files with different names are the same.
To solve this problem I've done the following:
Via a setting FAT32.IFS can be told to:
- Translate all long filenames internally to their short equivalences OR
- Use the long names internally, but hide all files or dirs with long names
from DOS sessions.
This setting can be changed (on the fly) with CACHEF32.EXE.
When using short names internally the following drawbacks occur:
- Current directory is shown as a short name (command line only)
- When deleting (long) files from the command line, the WPS doesn't
pickup the deletions.
When using long names internally the following drawbacks occur:
- Files and directories with long names are not visible in DOS sessions.
This is however the same as with HPFS.
CLEAN SHUTDOWN & CHKDSK
If Windows 95 (OSR2) shuts down properly, the clean shutdown status of the
disk is physically written on the disk. On next boot this state is checked,
and if the disk is not shutdown properly, SCANDISK is run.
FAT32.IFS also supports this feature. When CACHEF32 is called from the
config.sys, it checks, via a call to the IFS the state of each FAT32 drive.
For each drive that is not shutdown properly, CHKDSK is fired. If no errors
are found, or if only lost clusters where found and repaired, the drive is
If CHKDSK cannot solve the problem, the drive state is left dirty, and
NO FILES CAN BE OPENED AND NO DIRECTORIES CAN BE ADDED OR REMOVED.
Shutting down the disk, leaves the disk marked as not properly shutdown.
You should boot Windows 95 and run SCANDISK on the drive to fix the
F32STAT however, allows you for set the drive status, bypassing the normal
handling of FAT32.IFS. See the description of F32STAT for more information.
On most FAT32 drives the amount of free space is stored. FAT32.IFS will only
redetermine the amount of free space if:
- The disk was marked dirty on boot;
- The free space is set to -1 on the disk;
- The free space is not available on the disk.
FAT32.IFS will internally keep track of the free space and update it on disk
Cache performance is improved compared to version 0.10.
All of the code is in plain 16 bits C (All of OS/2's IFS's are 16 bits!).
No assembly language code is used.
The MONITOR function takes a lot of time. Be sure to switch if off if you don't
You should probably experiment with the CACHEF32 options to get the best
performance for your situation.
COMPATIBILITY WITH WINDOWS95
As far as I can tell, FAT32.IFS is fully compatible with the FAT32 support
in Windows 95. VFAT longnames can be used and on my PC, Windows95 doesn't
compain (anymore!) about long filenames I have created with FAT32.IFS.
The numeric tailed short names also seem to work ok. (The numeric tail option
cannot be switch off!)
File names are, as in Windows95 case preserving (in OS/2 sessions).
Creating a name in lower case will result in the file having a VFAT longname,
even if the name conforms to 8.3. The case will be preserved.
Last access dates are maintained by FAT32.IFS.
(but not the last access time since Win95 doesn't support it)
You can see these when using the detailed view of the drive object.
As stated, this version of FAT32 does NOT support extended attributes. This
means for one thing that REXX cmd files will have be to 'translated' on every
run since normally the 'tokenized' version of the cmd file is stored in EA's.
I haven't decided on HOW to implement EA's. The trick IBM used for FAT12 and
FAT16 partitions cannot be implemented on FAT32 because Microsoft has started
using the free space in each directory entry, so the two bytes IBM used for
storing a files EA location are no longer available.
IOCTL calls (category 8) are now passed through to OS2DASD. All calls
supported by OS2DASD.DMD are now also supported by the IFS.
Should FAT32.IFS fail to work, please check the following:
- Is a new drive letter assigned ? (If not OS2DASD.DMD failed)
If not, tell me.
- If you are not shure, try the /MONITOR parameter after FAT32.IFS,
and after reboot look with monitor for FS_MOUNT calls. Send me
- If a new drive letter is assigned, but FAT32.IFS fails,
please run DISKINFO and send me the output.
SUPPORTED IFS FUNCTIONS
FS_ALLOCATEPAGESPACE : No
FS_ATTACH : No
FS_CANCELLOCKREQUEST : No, function is implemented in the KERNEL
FS_CHDIR : Yes
FS_CHGFILEPTR : Yes
FS_CLOSE : Yes
FS_COMMIT : Yes
FS_COPY : No, function is simulated by command shell
FS_DELETE : Yes
FS_DOPAGEIO : No
FS_EXIT : Yes
FS_FILEATTRIBUTE : Yes
FS_FILEINFO : Yes
FS_FILEIO : No
FS_FILELOCKS : No, function is implemented in the KERNEL
FS_FINDCLOSE : Yes
FS_FINDFIRST : Yes
FS_FINDFROMNAME : Yes
FS_FINDNEXT : Yes
FS_FINDNOTIFYCLOSE : Obsolete in OS/2 WARP
FS_FINDNOTIFYFIRST : Obsolete in OS/2 WARP
FS_FINDNOTIFYNEXT : Obsolete in OS/2 WARP
FS_FLUSHBUF : Yes
FS_FSCTL : Yes
FS_FSINFO : Yes
FS_INIT : Yes
FS_IOCTL : Yes - LOCK & UNLOCK, others are passed to OS2DASD.
FS_MKDIR : Yes
FS_MOUNT : Yes
FS_MOVE : Yes
FS_NEWSIZE : Yes
FS_NMPIPE : No
FS_OPENCREATE : Yes
FS_OPENPAGEFILE : No
FS_PATHINFO : Yes
FS_PROCESSNAME : Yes
FS_READ : Yes
FS_RMDIR : Yes
FS_SETSWAP : No
FS_SHUTDOWN : Yes
FS_VERIFYUNCNAME : No
FS_WRITE : Yes
Version 0.10 - Initial Version
- Cache routines have been improved for performance. Removing 'old' sectors
from the cache is no longer needed. /T option for CACHEF32 has been
- CHKDSK: Is now able to fix incorrect free space count.
- CHKDSK: Lost cluster fix algoritm has been improved for performance.
- CHKDSK: Didn't recoqnize bad-sectors, has been fixed.
- CHKDSK: Had problems with recoqnition of some type of free clusters,
has been fixed.
- OS2DASD.DMD: Is now based on the latest version.
- Added PARTFILT.FLT to the archive.
- Added support for ReadOnly partitions. This is needed for PARTFILT.
- IOCTL Calls (category 8) are now passed throught to OS2DASD.
- The volume label was retrieved from the boot sector. However Win95
actually stores the Volume label in the root directory. The Volume label
now is taken from the root directory.
Also, the label can be set now. (The boot sector is however still updated)
- /Q switch of PARTFILT didn't work. Now it does.
- A problem was in CHGFILEPOINTER that could (theoretically) lead to an
trap (FAT32: FS_WRITE: No next cluster available").
- Corrected a logical error where renaming a file or directory to an existing
directory caused the file or directory to be moved into the target
directory. Now FAT32.IFS returns an error.
- Changed CHKDSK so that if an error is found in on of the FATs CHKDSK
continues, but ignores the /F switch. Previously, CHKDSK would not do any
- Renaming a file or directory from the workplace shell didn't work because
of two problems:
- the WPS uses a strange algoritm to determine of the IFS which
appearantly failed with FAT32. This has been corrected.
- FAT32.IFS does not support EA's (yet), the WPS renames a file, tries
to write EAs and since that fails renames the file back again.
Now FAT32 returns NO_ERROR on the call used to write EAs.
- CHKDSK now is able to fix cross-linked clusters on the disk.
- Fixed a problem with numeric tails shortnames. Files alway got ~1 instead
if an incrementing number. Has been fixed.
- Fixed a problem where files with longnames could sometimes not be found
which lead to duplicate filenames.
- Fixed a problem where scandisk would claim that a directory created by
FAT32.IFS contained invalid blocks.
- Fixed a (BIG) problem with files or directories with long names where
if such a file was opened in a DOS session and in an OS/2 session
simultaniously OS/2 was unable to see that the same file was opened.
- Fixed a problem where read-only executables could not be run.
- Fixed a problem where the algoritm used to determine the highest available
cluster number was incorrect.
- Fixed a problem were CHKDSK was unable to fix cross-linked files.
- Since some people complained that FAT32 would sometimes hang,
I have modified the internal semaphore mechanism so an error message will
appear if a semaphore remains blocked for more than a minute.
- Did a lot of work on Lazy write performance. Cache access is no longer
protected with a semaphore but with a per sector inuse flag.
- Fixed a problem that caused INSTALL and MINSTALL to abort when FAT32.IFS
was loaded. The problem had to do with argument checking with FS_IOCTL
- Fixed a problem that BRIEF, a populair editor under OS/2, trapped or hung
itself. The problem had to do with returning improperly formatted
information when querying EAs (FAT32.IFS does not support EAs!)
- Corrected a serious problem when a single file was opened more than once
and the file was modified using one of the instances. The other instance(s)
didn't pick up the changes and FAT32.IFS might trap.
- Didn't handle closes from child processes that inherited open files
properly so the final close would fail.