Re: Xfs Access to block zero exception and system crash

[Dave Chinner <david@fromorbit.com>]

On Sat, Jun 28, 2008 at 09:47:44AM -0700, Sagar Borikar wrote:
> > FWIW, can you send the output of xfs_growfs -n <mntpt> and details
> > of the partitioning and volume config?
....
> [root@NAS001ee5ab9c85 ~]# cat /etc/fstab
> /dev/root       /              ext2     rw,noauto         0      1
> proc            /proc          proc     defaults          0      0
> devpts          /dev/pts       devpts   defaults,gid=5,mode=620   0
> 0
> tmpfs           /tmp           tmpfs    defaults          0      0
> /dev/RAIDA/vol  /mnt/RAIDA/vol  xfs     defaults,usrquota,grpquota
> 0 0
> /mnt/RAIDA/vol/sh       /mnt/ftp_dir/sh none    rw,bind 0 0
> /mnt/RAIDA/vol/.autohome/       /mnt/ftp_dir/homes      none    rw,bind
> 0 0
> 
> [root@NAS001ee5ab9c85 ~]# fdisk -l
> 
> Disk /dev/scsibd: 257 MB, 257425408 bytes
> 8 heads, 32 sectors/track, 1964 cylinders
> Units = cylinders of 256 * 512 = 131072 bytes
> 
>       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?

> 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....

> 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.
-- 
Dave Chinner
david@fromorbit.com