2008-05-28 11:52:04 Ext2 Corruptions During Power-Loss

David Kasper (UNITED STATES)

Message: 56357

I have successfully integrated the BF-537 STAMP board including CompactFlash daughter card (ADDS-BF537-STEXT) into a product and am using the EXT2 file system. However, serious file system corruptions occur if power is lost when the drive is mounted. I was considering the following approaches:

- Provide a power-loss interrupt which would flush the data cache and un-mount the drive

- Evaluate the journaling EXT3 file system

Any thoughts on how to solve this problem?

Thanks,

David Kasper

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2008-05-28 12:29:59 Re: Ext2 Corruptions During Power-Loss

Mike Frysinger (UNITED STATES)

Message: 56360

EXT2 requires a clean shutdown and it's always been that way ... if you need to handle unexpected power loss, you need to use a journaled filesystem

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2008-06-05 17:37:33 Re: Ext2 Corruptions During Power-Loss

David Kasper (UNITED STATES)

Message: 56764

Mike,

I tried EXT3 but it seems the journal got corrupted after a couple of power loss events. I lost the entire data directory after running e2fsck. Do you think I would have better luck with JFS or another file system? The error displayed while trying to mount is listed below:

/dev/hda1: recovering journal

/dev/hda1: Note: if there is several inode or block bitmap blocks

which require relocation, or one part of the inode table

which must be moved, you may wish to try running e2fsck

with the '-b 32768' option first. The problem may lie only

with the primary block group descriptor, and the backup

block group descriptor may be OK.

/dev/hda1: Block bitmap for group 2 is not in group. (block 8)

/dev/hda1: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.

(i.e., without -a or -p options)

EXT3-fs error (device hda1): ext3_check_descriptors: Block bitmap for group 2 not in group (block 8)!

EXT3-fs: group descriptors corrupted!