[SATLUG] Disk recovery

[Bruce Dubbs]

tom weeks wrote:
> On Wednesday 20 June 2007 15:39, Bruce Dubbs wrote:
>> I have a friend with a corrupted disk.  Evidently this is part of a
>> linksys backup system.  He removed the disk and put it into a PC.  After
>> working with him I found out it was:
>>
>> Disk /dev/hdb:  81.9GB, 81964302336 Bytes
>> 16 Heads, 63 Sectors/Track, 158816 Cylinders
>> Units = Cylinders of 1008 * 512 = 516096 bytes
>>
>> Device boot        Start        End        Blocks        ID      System
>> /dev/hdb1              2     158563      79915248        83      Linux
>> /dev/hdb2         158564     158816        127512        82      Linux
>> swap / Solaris
>>
>> We tried running e2fsck but it couldn't find a valid superblock.  I had
>> him dump the block with the first superblock (2nd 1K block) and it was
>> all zeros.
> 
> I'm assuming here that it IS either ext2 or 3.
> 
> If so..
> Scan it for alternate super blocks:
> # dumpe2fs /dev/sda2|grep super
> dumpe2fs 1.39 (29-May-2006)
> Filesystem features:      has_journal ext_attr resize_inode dir_index filetype 
> needs_recovery sparse_super
>   Primary superblock at 1, Group descriptors at 2-2
>   Backup superblock at 8193, Group descriptors at 8194-8194
>   Backup superblock at 24577, Group descriptors at 24578-24578
>   Backup superblock at 40961, Group descriptors at 40962-40962
>   Backup superblock at 57345, Group descriptors at 57346-57346
>   Backup superblock at 73729, Group descriptors at 73730-73730
> 
> 
> Then you can try fscking with one of those with:
> # fsck  -b 73729
> 
> 
> If it looks like it's going to work.. then use with the -y switch.


Thanks Tom.  We did try to that with the superblocks from mke2fs -n.
I'll have him try  dumpe2fs.

  -- Bruce