Re: mount: /dev/md0: can't read superblock

Justin Piszcz
2007-10-22T11:16:29Z

I degragment many arrays (sw raid) and single disks without any problems,
not sure what your issue was.

On Sun, 21 Oct 2007, Greg Martyn wrote:

> Thank you Eric and David. xfs_repair repaired the filesystem. I forgot
> to save the output of xfs_fsr (in case you were curious about what
> went wrong), but everything seems to be working fine again.
>
> I just won't be defragging again any time soon ;-)
>
> Thanks,
> greg
>
> On 10/21/07, David Chinner <dgc@sgi.com> wrote:
>> On Sun, Oct 21, 2007 at 07:24:45PM -0500, Eric Sandeen wrote:
>>> Greg Martyn wrote:
>>>> Hi all,
>>>> After running "xfs_fsr -v /home", I got a bunch of error messages
>>>> saying that certain files (/home/.[three letters that i forgot])
>>>> couldn't be removed. After that, my system stopped working properly,
>>>> so I restarted. Now:
>>>>
>>>> [root@localhost ~]# mount /dev/md0 /home/
>>>> mount: /dev/md0: can't read superblock
>>>>
>>>> uh oh.
>>>
>>> dmesg says it's corrupted.
>>>
>>> You should probably run repair on it. But being raid, if something went
>>> wrong w/ the raid, that could make it worse... run xfs_repair -n and see
>>> what it *would* fix.
>>
>> xfs_repair does not check everything in the filesystem - some things it
>> simply rebuilds - like the free space btrees. you want to run xfs_check
>> to determine if the free space btrees are corrupt on disk or not.... ;)
>>
>> Cheers,
>>
>> Dave.
>> --
>> Dave Chinner
>> Principal Engineer
>> SGI Australian Software Group
>>
>
>