How to fix bad superblock or xfs_repair: error - read only 0 of 512 bytes

[Christian Kildau]

On Jan 23, 2012, at 5:31 AM, Dave Chinner wrote:

> On Sat, Jan 21, 2012 at 11:29:15AM +0100, Christian Kildau wrote:
>> Sorry if this message appears twice!
>> 
>> 
>> 
>> Hello,
>> 
>> I'm having some very serious issues with XFS after upgrading from a
>> Linux Distro running Ubuntu 2.6.32 to 3.2.
>> 
>> It seems like my filesystems are damaged after attaching them to a
>> Linux 3.2 server. I am also no longer able to mount the hdd on the old
>> server that is still running 2.6.32!
> 
> I take it that you are using external storage of some kind? Can you
> describe it?

This hdd is connected via e-sata, but it doesn't make any difference if I directly connect it internally via sata.
Also it doesn't make any difference if I connect it back to the 'old' server

> 
>> (I created the xfs filesystem on the entire hdd, not on a partition,
>> so /dev/sdd is not a typo)
>> 
>> $ sudo mount -t xfs /dev/sdd /media/
>> mount: /dev/sdd: can't read superblock
>> (dmesg)
>> [236659.912663] attempt to access beyond end of device
>> [236659.912667] sdd: rw=32, want=2930277168, limit=2930275055
>> [236659.912670] XFS (sdd): last sector read failed
> 
> So XFS has asked to read 2113 sectors beyond the size of the device
> that the kernel is reporting. What is the output of
> /proc/partitions?

$ grep sdd /proc/partitions 
   8       64 1465137527 sdd

> 
>> $ sudo xfs_check /dev/sdd
>> xfs_check: error - read only 0 of 512 bytes
>> 
>> $ sudo xfs_repair /dev/sdd
>> Phase 1 - find and verify superblock...
>> xfs_repair: error - read only 0 of 512 bytes
> 
> So both buffered and direct IO to the first block in the block
> device are failing. I'd say your problems have nothing to do with
> XFS. However, can you strace them and find out what the error that
> is occuring actually is?

Strace is giving me:
wait4(-1, xfs_check: /dev/sdd is not a valid XFS filesystem (unexpected SB magic number 0x00000000)
xfs_check: WARNING - filesystem uses v1 dirs,limited functionality provided.
xfs_check: read failed: Invalid argument
cache_node_purge: refcount was 1, not zero (node=0x21ecef0)
xfs_check: cannot read root inode (22)
bad superblock magic number 0, giving up

I attached the entire strace logs to this email.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: xfs_check.strace
Type: application/octet-stream
Size: 3712 bytes
Desc: not available
URL: <http://oss.sgi.com/pipermail/xfs/attachments/20120123/1167752d/attachment.dll>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: xfs_repair.strace
Type: application/octet-stream
Size: 7958 bytes
Desc: not available
URL: <http://oss.sgi.com/pipermail/xfs/attachments/20120123/1167752d/attachment-0001.dll>
-------------- next part --------------


Do you have any idea what has caused this or how to fix it?

Thanks in advance!
Chris