RE: cluster size=0

[Paul Bunn <Paul UltraBac com>]

Mysterious.

If you use DISKEDIT from the Norton tools, or your favorite disk-sector editor,
you can load the boot-sector from the drive.  For partition 1 this means that you
need to load sector 0/1/1 (usually LBA 63 or 255 depending on
geometry/translation).  You will find the cluster-size set at offset 0x0d in that
sector, and it is defined as number of sectors per cluster and the value must be a
power of 2:  1, 2, 4, 8 etc.
DISKEDIT should let you view the data as a FAT boot-sector (FAT32 is a superset of
the FAT data) so you can review the other values too.

Regards,

Paul Bunn, UltraBac.com, 425-644-6000
Microsoft MVP - WindowsNT/2000
http://www.ultrabac.com
 

-----Original Message-----
From: James Fowler [mailto:santiago@cx908962-l.mesa1.az.home.com]
Sent: Saturday, March 24, 2001 3:31 AM
To: axp-list@redhat.com
Subject: OT: cluster size=0


Sorry for the OT, but I am really stumped on this one.  I was attempting
to back up a win95 FAT32 partition by doing a 'tar -cvf' on it and storing
the tar file on another disk.  I had some problems as the tar file would
exceed 2GB and then tar would die telling me that the archive was too big
to continue (even though there was 15GB still available on the device
where the archive was being written).  [I figure that the 2GB things was
due to the fact that it was a 2.2.14 kernel that must not have supported a
file size above 2GB. This seems less important right now.]
Some how the cluster size on the FAT32 parition got changed to 0.  The
partition is still intact.  I haven't changed the parition type, formated,
reformated or any of the above. Nothing has been written to the partition
and the parition itself still shows to be intact.  I can even boot from
the drive (using lilo on the MBR) as long as I don't boot from that
parition (partition 1, on my machine /dev/hda1 occupying sec 1-511).
Roughly a 4GB partition.

How do I get the cluster size set back to what it was (the standard
win95 FAT32 size) or alternatively, get the data off of that partition.  I
haven't had any luck attempting to mount it under linux.  I have tried
dosfsck, fsck.vfat/fsck.msdos, partition magic 4.0, revival, PQDI, Norton
Disk Doctor (old Dos version).  I haven't allowed anything to write to the
disk.  I have only attempted reads.  The data is important or I would just
back up the rest of the disk and repartition it.