Re: NFS and partitioned md

[David Greaves <david@dgreaves.com>]

Neil Brown wrote:
> On Tuesday June 27, bugtraq@smoula.net wrote:
>> Hi,
>>
>> thx for your interrest,
>>
>> Neil Brown píše v Út 27. 06. 2006 v 10:32 +1000:
>>> So I suspect there is something else going on that has nothing to do
>>> with the usage of partitioned md.... then again, maybe there is some
>>> weird sign extension happening to '254' somewhere, though that would
>>> be terribly strange.
>> (as I look on that it comes on my mind, that problem could be minor
>> longer than 1 byte)
>>
> 
> Exactly.  4105 > 256.  Such devices need a different format filehandle
> which didn't work until very recently due to a bug (obviously no-one
> tried it until recently).
> 
> The patch below fixes the kernel so that this will work.
> Alternately use md_d0 md_d1, md_d2, or md_d3.  Then it will work with
> no patches.

FWIW (and google) I have just encountered this problem on 2.6.16.9 server.

My error message with the NFS mount failing was:
mount teak:/media /mnt/test
mount: teak:/media: can't read superblock

teak:~# ll /dev/media*
brw-rw---- 1 root disk 254, 8128 2006-07-18 18:39 /dev/media
brw-rw---- 1 root disk 254, 8129 2006-07-18 18:39 /dev/media1
brw-rw---- 1 root disk 254, 8130 2006-07-18 18:39 /dev/media2
brw-rw---- 1 root disk 254, 8131 2006-07-18 18:39 /dev/media3
brw-rw---- 1 root disk 254, 8132 2006-07-18 18:39 /dev/media4

I rebooted to use /dev/md_d0 and /dev/md_d0p1 and it's fine.

David