Re: raid50 and 9TB volumes

[Raz <raziebe@xxxxxxxxx>]

On 7/16/07, David Chinner <dgc@xxxxxxx> wrote:
> On Mon, Jul 16, 2007 at 03:42:28PM +0300, Raz wrote:
> > Hello
> > I found that using xfs over raid50, ( two raid5's 8 disks each and
> > raid 0 over them ) crashes the file system when the file system is ~
> > 9TB. crashing is easy: we simply create few hundred of files, then
> > erase them in bulk. the same test passes in 6.4TB filesystems.
> > this bug happens in 2.6.22 as well as 2.6.17.7.
> > thank you .
> >
> > 4391322.839000] Filesystem "md3": XFS internal error
> > xfs_alloc_read_agf at line 2176 of file fs/xfs/xfs_alloc.c.  Caller
> > 0xc10d31ea
> > [4391322.863000]  <c10d36e9> xfs_alloc_read_agf+0x199/0x220
> > <c10d31ea> xfs_alloc_fix_freelist+0x41a/0x4b0
>
> Judging by the kernel addresses (<c10d36e9>) you're running
> an i386 kernel right? Which means there's probably a wrapping
> issue at 8TB somewhere in the code which has caused an AGF
> header to be trashed somewhere lower down in the filesystem.
> what does /proc/partitions say? I.e. does the kernel see
> the whole 9TB of space?
>
> What does xfs_repair tell you about the corruption? (assuming
> it doesn't OOM, which is a good chance if you really are on
> i386).
>
> Cheers,
>
> Dave.
> --
> Dave Chinner
> Principal Engineer
> SGI Australian Software Group
Well you are right.  /proc/partitions  says:
....
   8   241  488384001 sdp1
   9     1 3404964864 md1
   9     2 3418684416 md2
   9     3 6823647232 md3

while xfs formats md3 as 9 TB.
If i am using LBD , what is the biggest size I can use on i386 ?

many thanks
raz

--
Raz