# Corrupted block bitmap on EXT3 disk.[solved]

## nw_biohazard

Hi,

I'm hoping someone can help me with a disaster that occurred yesterday. I did a full update several days ago and all seemed to be well.

When issuing basic commands, I immediately ran into problems such as my home directory appearing to be empty, various commands not found, and KDE eventually crashing.

I tried rebooting and that failed with a message similar to

"No filesystem could mount root, tried: etx3 ........."

My /etc/fstab looks like this:

/dev/sda1               /boot           ext2            noauto,noatime  1 2

/dev/sda2               none            swap            sw              0 0

/dev/sda3               /               ext3            noatime         0 1

/dev/cdrecorder         /mnt/cdrecorder auto            noauto,user     0 0

/dev/dvd                /mnt/dvd        auto            noauto,user     0 0

proc                    /proc           proc            defaults        0 0

shm                     /dev/shm        tmpfs           nodev,nosuid,noexec    $

/dev/sdb1              /data1          ext3            noatime         0 2

/dev/sdb2              /data2          ext3            noatime         0 2

As a first step, I tried booting from a boot DVD and mounting my user directories:

```

mount /dev/sdb3 /mnt/gentoo

```

I get:

```

livecd kernel: EXT3-fs error (device sda3): ext3_check_descriptors: Block bitmap for group 8 not in group (block 65569188)!

livecd kernel: EXT3-fs: group descriptors corrupted!

```

This seems like it might be some sort of disk error but I am in way over  my head in terms of trying to fix it or at least get a fresh backup of my data.

This thread seemed like it might be useful but before I begin on that, any opinions as to whether I'm on the right track?

https://forums.gentoo.org/viewtopic-t-433796-highlight-ext3fs+group+descriptors+corrupted.html

Thanks!Last edited by nw_biohazard on Sat Feb 12, 2011 3:27 pm; edited 1 time in total

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## Hu

Am I correct from your phrasing that the first indication of trouble was the absence of expected files?  Are there any messages in dmesg regarding hardware errors?

If you have it, you might be able to use /usr/sbin/smartctl (from sys-apps/smartmontools) to start a drive self-test and/or to view the drive error log.  You could try a filesystem check, but I suggest finding the origin of the problem before you allow any further modifications to that partition.  Rewriting a filesystem on a failing drive could easily do more harm than good.

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## nw_biohazard

Yes, the first indication of trouble was missing files. I didn't see anything in dmesg that I could interpret as hardware errors.

I'm in the livecd so I don't have /usr/sbin/smartctl.

If I do

```

fsck /dev/sd3

e2fsck 1.41.9 (22-Aug-2009)

fsck.ext3: Superblock invalid, trying backup blocks...

Superblock needs_recovery flag is clear, butjournal has data.

Recovery flag not set in backup superblock, so running journal anyway.

/dev/sda3: recovering journal

Resize inode not valid. Recreate<y>? cancelled!

```

Do you think it is worth trying to fix it with fsck?

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## Hu

What other option do you have than to try to fix it?  You can wipe and remake the filesystem or you can try to repair the existing filesystem.  If you do not have a current backup, I suggest creating one as soon as you manage to mount the filesystem.

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## nw_biohazard

fsck seemed to repair it.

I managed to backup all of the data.

Thanks for the help!

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