From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.5) Gecko/20031007 Firebird/0.7 Description of problem: I a usb-storage device with a 40GB FAT32 formated disk in it. When ever I write to it and then run fsck.vfat on it I get: FATs differ but appear to be intact. Use which FAT ? Woe unto you if you choose the second FAT. You will usually lose all of the files you just added. If you choose the first FAT everything is fine. All of my files seem to be there... Version-Release number of selected component (if applicable): dosfstools-2.8-11 How reproducible: Always Steps to Reproduce: 1. Copy a bunch of files to USB device 2. unmount it 3. run fsck.vfat on the device Actual Results: [root@cheddar root]# fsck.vfat -vr /dev/sda1 dosfsck 2.8 (28 Feb 2001) dosfsck 2.8, 28 Feb 2001, FAT32, LFN Warning: FAT32 support is still ALPHA. Boot sector contents: System ID "DIVER100" Media byte 0xf8 (hard disk) 512 bytes per logical sector 8192 bytes per cluster 32 reserved sectors First FAT starts at byte 16384 (sector 32) 2 FATs, 32 bit entries 19534848 bytes per FAT (= 38154 sectors) Root directory start at cluster 2 (arbitrary size) Data area starts at byte 39086080 (sector 76340) 4878986 data clusters (1313947648 bytes) 63 sectors/track, 255 heads 32 hidden sectors 78140128 sectors total FATs differ but appear to be intact. Use which FAT ? 1) Use first FAT 2) Use second FAT ? 1 Checking for unused clusters. Checking free cluster summary. Perform changes ? (y/n) y /dev/sda1: 3339 files, 576498/4878986 clusters Expected Results: fsck.vfat would tell me all is well. Additional info:
# fdisk -l /dev/sda Disk /dev/sda: 3253 MB, 3253469184 bytes 128 heads, 63 sectors/track, 788 cylinders Units = cylinders of 8064 * 512 = 4128768 bytes Device Boot Start End Blocks Id System /dev/sda1 * 1 533 2149024+ 83 Linux /dev/sda2 534 788 1028160 b W95 FAT32 #fsck.vfat -vr /dev/sda2 dosfsck 2.8 (28 Feb 2001) dosfsck 2.8, 28 Feb 2001, FAT32, LFN Warning: FAT32 support is still ALPHA. There are differences between boot sector and its backup. Differences: (offset:original/backup) 65:01/00 1) Copy original to backup 2) Copy backup to original 3) No action ? ^^^^^^^^^^^^ problem # mkfs.vfat /dev/sda2 mkfs.vfat 2.8 (28 Feb 2001) # fsck.vfat /dev/sda2 dosfsck 2.8, 28 Feb 2001, FAT32, LFN Warning: FAT32 support is still ALPHA. /dev/sda2: 0 files, 1/256534 clusters # mount -t vfat /dev/sda2 /mnt/usb # cp -fR /usr/share/doc/rpm-devel-4.3.2 /mnt/usb # umount /mnt/usb # fsck.vfat /dev/sda2 dosfsck 2.8, 28 Feb 2001, FAT32, LFN Warning: FAT32 support is still ALPHA. /dev/sda2: 674 files, 5343/256534 clusters It looks a problem fix rebuild filesystem on your device. The current fcsk.vfat is probably not compatible with older version(s).