I've done a lot of designs with Compact Flash where we couldn't control when we got powered down so we always used .ext3 and recovered nicely. Our board is currently using the non-mmu because of memory constraints. A customer wants to use FAT32 -- I'm using some newer Compact Flash drives with built in power down circuitry. The compact flash data doesn't get corrupt BUT when I do a "dosfsck -a" ON THE non-mmu system: (I've ported dosfstools 3.0.5 into the release) at boot I see "logical sector size is zero" so basically it DOES NOT check the disk. ON THE MMU system (ver. 3.0.5): at boot it actually checks the disk (well it accesses the disk for awhile) and then just gives me a message: /dev/sda1: 10 files, 517462/1999613 clusters Can anyone help me understand why the MMU system doesn't report the "logical sector..." while the non-mmu system does? I want to make sure that the disks can be written to. Should the disks be reformatted when this message is seen? Is there a way in the non-mmu system to fix the "logical sector size is zero" at boot time? I just need to know enough about FAT32 and dosfsck so we don't lose data & we can recover from any corruption of the disk.