FAQ   Search   Memberlist  
Profile    Log in to check your private messages    Register    Log in
EXT2-fs: group descriptors corrupted! (external USB drive)

 
Post new topic   Reply to topic    BLAG Forum Index -> support
View previous topic :: View next topic  
Author Message
pistonbrew
PostPosted: Tue Jul 01, 2008 10:47 am    Post subject: EXT2-fs: group descriptors corrupted! (external USB drive) Reply with quote

can anyone suggest a way of fixing the fs on my 500gb external USB drive?
it has a single ext2 partition, sdb1. actually i thought it was ext3, but the output below suggests not.
using QTparted, the disk appears to be about 50% full, so i guess the data is still there. i'd like to save it, as most of it is not backed up (in fact, some of it *is* backups!)

i get:
Code:
[root@blagged-up bob]# mount /dev/sdb1 /media/
mount: wrong fs type, bad option, bad superblock on /dev/sdb1,
       missing codepage or other error
       In some cases useful info is found in syslog - try
       dmesg | tail  or so


and then:
Code:
[root@blagged-up bob]# dmesg | tail
EXT2-fs error (device sdb1): ext2_check_descriptors: Block bitmap for group 512 not in group (block 1869750373)!
EXT2-fs: group descriptors corrupted!
EXT2-fs error (device sdb1): ext2_check_descriptors: Block bitmap for group 512 not in group (block 1869750373)!
EXT2-fs: group descriptors corrupted!
EXT2-fs error (device sdb1): ext2_check_descriptors: Block bitmap for group 512 not in group (block 1869750373)!
EXT2-fs: group descriptors corrupted!


any tips? i notice blag70k doesn't have fsck or tune2fs by default. i take it i should start by installing them?

Saint of Killers
PostPosted: Tue Jul 01, 2008 1:33 pm    Post subject: Reply with quote

Tried installing and running testdisk? Usually does the job at recovering files/filesystems for me.
jebba
PostPosted: Tue Jul 01, 2008 2:27 pm    Post subject: Re: EXT2-fs: group descriptors corrupted! (external USB dri Reply with quote

pistonbrew wrote:
any tips? i notice blag70k doesn't have fsck or tune2fs by default. i take it i should start by installing them?


Ya, they are there, they probably aren't in your $PATH.

/sbin/fsck
/sbin/tune2fs

Code:
su -
umount /dev/sdb1
fsck -vvv /dev/sdb1

pistonbrew
PostPosted: Tue Jul 01, 2008 2:43 pm    Post subject: Reply with quote

thanks guys, will try these when i get home.

jebba - i didn't try that.. oops!

googling around, lots of requests for info on this problem (or similar), but not many resolutions :-(

we'll see how we go...

pistonbrew
PostPosted: Tue Jul 01, 2008 8:46 pm    Post subject: Reply with quote

just trying testdisk so far. it failed to find any partitions during the quick and deeper scans, but it is currently finding some superblocks.
not sure if that's good news or not!


bit of a crash course in ext filesystems, this :-(

jebba
PostPosted: Tue Jul 01, 2008 10:51 pm    Post subject: Reply with quote

Definitely check out fsck, as it is the main tool for fixing ext2/3 filesystems (especially before doing any crazy partitioning moves or anything like that ;)
pistonbrew
PostPosted: Wed Jul 02, 2008 8:02 am    Post subject: Reply with quote

well i *think* i've saved my data, thanks to a bit of all the advice here.

long story short (involving thousands of inodes...), i can mount /dev/sdb1 now, but all the data is in the lost+found.

according to nautilus, lost+found contains 43575 items, totalling 201.5 GB - which is about the same size as the data on the lost partition..
i guess the only way to restore it is manually, which would probably take too long to be practical.

unless, again, anyone knows of a recovery tool?

pistonbrew
PostPosted: Wed Jul 02, 2008 8:58 am    Post subject: Reply with quote

on further inspection, a lot of stuff has landed in recognisable directories, so i can just copy that to another disk.

the rest, i might be able to weed out using photorec, which is bundled with testdisk.

so, there goes a day i will never get back ;-)
thanks for helping, all!

jebba
PostPosted: Wed Jul 02, 2008 8:58 pm    Post subject: Reply with quote

Cool, glad you saved your data at least. The lost+found directory will often have "all" the files, but now given totally weird names...
jebba
PostPosted: Thu Jul 03, 2008 9:26 am    Post subject: Reply with quote

i just saw this somewhere
http://www.informationweek.com/news/storage/disaster_recovery/showArticle.jhtml?articleID=208403254

pistonbrew
PostPosted: Thu Jul 03, 2008 3:14 pm    Post subject: Reply with quote

i must say, testdisk/photorec worked really well. i recovered what i could by hand from lost+found, then photorec'd the rest - which mainly turned out to be junk *.png's from my gnome thumbnails, but it did rescue some important stuff too. wish i'd known about it before.
Display posts from previous:   
Post new topic   Reply to topic    BLAG Forum Index -> support
Page 1 of 1

Protected by Anti-Spam ACP