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

[Christian Kildau <lists@xxxxxxxxxxxxx>]

On Jan 24, 2012, at 3:12 PM, Roger Willcocks wrote:

> 
> On Tue, 2012-01-24 at 11:13 +0100, Christian Kildau wrote:
>> Top posting... sorry.
>> 
>> I have now found dozens of other users with a similar issue! e.g.
>> http://www.linuxquestions.org/questions/linux-general-1/cannot-mount-hard-disk-block-count-exceeds-size-of-device-bad-partition-table-880149/
>> 
>> To make it short all of these users were running ext4 and a fs resize to the 
>> new geometry fixed their problems! Sadly XFS doesn't support shrinking the 
>> fs(?).
>> 
> 
> It seems fairly clear that your drive or the bios is lying about its
> capacity. The filesystem occupies the entire disk, but the disk has
> become 'smaller'. A quick web search suggests a 'hidden protected area'
> - the two block counts in this link line up with the before and after
> sizes you're seeing:
> 
> http://lime-technology.com/forum/index.php?topic=13440.0;wap2
> 
> It would be instructive to see what 'hdparm -N /dev/sdd' says on your
> system. And a dmesg log would be handy too.
> 
> Note that this is /not/ a problem with xfs. The right fix is to tell the
> drive to report its actual capacity, not to shrink the filesystem.

I do understand that is definitely not an XFS issue, but some strange issue 
with ubuntu or their kernel patches...

I got my data back by dumping the entire hdd (it was partitionless 
nevertheless) to a bigger 2TB hdd.
XFS mounts without any problems and I can restore my data.

Thanks all for your help!