nfs client hanging

[Guillaume Rousse]

J. Bruce Fields a écrit :
> On Wed, Jul 02, 2008 at 01:19:17PM -0400, Trond Myklebust wrote:
>> On Wed, 2008-07-02 at 14:00 +0200, Guillaume Rousse wrote:
>>> Actually, I spoke too fast, the problem also occurs with files hosted on 
>>> the linux server, with a different scenario:
>>> - the connection is still present when the hang occurs
>>> - rpc.idmapd seems to have crashed (no trace in the logs, tough, as 
>>> verbosity was set to 0)
>>>
>>> Full client (rpc + nfs flags) and servers  (rpc + nfsd flags) logs are 
>>> available at http://www.zarb.org/~guillomovitch/{client,server}.log.
>>>
>>>  From what I understand, this is a normal revalidation operation:
>>> Jul  2 04:35:00 chatelet kernel: NFS: revalidating (0:15/7322625)
>>> Jul  2 04:35:02 chatelet kernel: NFS: nfs_update_inode(0:15/7322625 ct=2 
>>> info=0xe)
>>> Jul  2 04:35:02 chatelet kernel: NFS: (0:15/7322625) revalidation complete
>>>
>>> Starting from 5:13, revalidation on this inode doesn't complete anymore, 
>>> which seems to imply the problem occurs between 04:35:02 and 05:13:47:
>>> Jul  2 05:13:47 chatelet kernel: NFS: revalidating (0:15/7322625)
>>> Jul  2 08:26:13 chatelet kernel: NFS: revalidating (0:15/7322625)
>>>
>>> But I don't find anything really suspicious :(
>> If the idmapper was crashed, then that is quite sufficient to explain
>> your trouble. The above GETATTR calls rely on the idmapper to translate
>> NFSv4 names into uids and gids, and will hang if it is not responding.
> 
> And figuring out why idmapd crashed would be a really good thing to do
> in any case....  So that's the question to work on, I think.
Unfortunatly, this scenario only occurs with file systems mounted from 
the linux NFS server, not with the filer, which may me think I'm 
actually facing two different issues. I stopped NFS mounting of home 
directories on the host where this problem occured, due to growing users 
pression, so I have to set up a test host from scratch to track this case.
-- 
Guillaume Rousse
Moyens Informatiques - INRIA Futurs
Tel: 01 69 35 69 62