Re: Xfs Access to block zero exception and system crash

[Sagar Borikar <sagar_borikar@pmc-sierra.com>]

Dave Chinner wrote:
> On Sat, Jun 28, 2008 at 09:47:44AM -0700, Sagar Borikar wrote:
>   
> Device Boot Start End Blocks Id System
>> /dev/scsibd1             126         286       20608   83  Linux
>> /dev/scsibd2             287        1023       94336   83  Linux
>> /dev/scsibd3            1149        1309       20608   83  Linux
>> /dev/scsibd4            1310        2046       94336   83  Linux
>>     
>
> I'd have to assume thats a flash based root drive, right?
>
>   
That's right,
>> Disk /dev/md0: 251.0 GB, 251000160256 bytes
>> 2 heads, 4 sectors/track, 61279336 cylinders
>> Units = cylinders of 8 * 512 = 4096 bytes
>>
>> Disk /dev/md0 doesn't contain a valid partition table
>>
>> Disk /dev/dm-0: 107.3 GB, 107374182400 bytes
>> 255 heads, 63 sectors/track, 13054 cylinders
>> Units = cylinders of 16065 * 512 = 8225280 bytes
>>     
>
> Neither of these tell me what /dev/RAIDA/vol is....
> It is the device node to which /mnt/RAIDA/vol is mapped to. Its a JBOD with 233 GB size.
>   
>> But still the issue is why doesn't it happen every time and less stress?
>>
>> I am surprised to see to let this happen immediately when the
>> subdirectories increase more than 30. Else it decays slowly.
>>     
>
> So it happens when you get more than 30 entries in a directory
> under a certain load? That might be an extent->btree format
> conversion bug or vice versa. I'd suggest setting up a test based
> around this to try to narrow down the problem.
>
> Cheers,
>
> Dave.
>   
Thanks for all your help. Shall keep you posted with the progress on 
debugging.

Regards
Sagar