Re: fsck.ext4 taking months

[Ric Wheeler <rwheeler@redhat.com>]

On 03/27/2011 07:28 AM, Christian Brandt wrote:
> Situation: External 500GB drive holds lots of snapshots using lots of
> hard links made by rsync --link-dest. The controller went bad and
> destroyed superblock and directory structures. The drive contains
> roughly a million files and four complete directory-tree-snapshots with
> each roughly a million hardlinks.
>
> Tried
>
> e2fsck 1.41.12 (17-May-2010)
>          Benutze EXT2FS Library version 1.41.12, 17-May-2010
>
> e2fsck 1.41.11 (14-Mar-2010)
>          Benutze EXT2FS Library version 1.41.11, 14-Mar-2010
>
> Symptoms: fsck.ext4 -y -f takes nearly a month to fix the structures on
> a P4@2,8Ghz, with very little access to the drive and 100% cpu use.
>
> output of fsck looks much like this:
>
> File ??? (Inode #123456, modify time Wed Jul 22 16:20:23 2009)
>    block Nr. 6144 double block(s), used with four file(s):
>      <filesystem metadata>
>      ??? (Inode #123457, mod time Wed Jul 22 16:20:23 2009)
>      ??? (Inode #123458, mod time Wed Jul 22 16:20:23 2009)
>      ...
> multiply claimed block map? Yes
>
> Is there an adhoc method of getting my data back faster?
>
> Is the slow performance with lots of hard links a known issue?
>

Sounds like a configuration that might well require lots of memory to cache your 
allocated inodes, etc. How much memory do you have in the box running fsck? Any 
sense (vmstat, etc) what the box is spending its time doing?

Ric