Re: EXT4-fs: group descriptors corrupted!

On 02/25/2009 03:30 PM, Theodore Tso wrote:

On Wed, Feb 25, 2009 at 02:39:31PM -0600, Ron Johnson wrote:

quoted

These are the relevant Debian Sid package versions:
e2fsprogs                1.41.3-1
linux-source-2.6.28      2.6.28-2~snapshot.12850

Since I built the fs with extents enabled, I am hesitant to run fsck on 
it because I've read that it doesn't yet support extents.

As you can see from the dmesg snippets, one of my ext4 file systems  
mounted perfectly.  The one that didn't is an lvm2 "array", which seems 
to be consistent.

E2fsck 1.41.3 does actually have extent support, but let's not be too
hasty to run e2fsck just yet.

Can you send me the output of "dumpe2fs -o superblock=32768
/dev/main_huge_vg/main_huge_lv" and see how it compares to the
dumpe2fs of your primary superblock?

# dumpe2fs -f -o superblock=32768 /dev/main_huge_vg/main_huge_lv | 
head -n800 > main_huge_lv.dump.sb32768.txt
dumpe2fs 1.41.3 (12-Oct-2008)
ext2fs_read_bb_inode: Invalid argument

http://members.cox.net/ron.l.johnson/main_huge_lv.dump.sb32768.txt

It looks like your block group descriptors were totally scribbled
upon.

There system cleanly shut down.  (Or, at least, I didn't notice 
anything obviously wrong.)

       How and why it happened, I'm not sure.  But before we do
anything else, let's check out the backup descriptors and make sure
they are sane.

-- 
Ron Johnson, Jr.
Jefferson LA  USA

The feeling of disgust at seeing a human female in a Relationship
with a chimp male is Homininphobia, and you should be ashamed of
yourself.