Re: nfsd4_stateowners problem

["J. Bruce Fields" <bfields@fieldses.org>]

On Fri, Aug 27, 2010 at 01:48:23PM -0400, Peter Skensved wrote:
> 
>   I'm looking for pointers and information on how to debug and annoying NFS
> problem that has been bugging us for a long time. The problem is that the number
> of nfsd4_stateowners keeps increasing until all low memory is exhausted and
> the oom-killer is invoked. The severity of the problem has changed over time
> with different kernels. At present it takes about 5 weeks for the size to
> grow to 500 Mb  ( kernel 2.6.18-194.8.1.el5PAE, CentOS5.5 ). Restarting 
> nfs clears up the problem but it is definitely not the preferred solution. 
> 
>  The increase in the number of nfsd4_stateowners appears to happen in bursts.
> Nothing happens for long times and I suddenly see a burst. I've tried ( briefly )
> to turn on all logging in rpcdebug and have run tcpdump while watching slabtop
> but there is too much output to be able to see if there is anything strange
> happening. So - my question is : how do I limit the diagnostic output to what
> is relevant ? What are the modules and flags that I should be looking at ?
> Any other info I should bemonitoring ? /proc/fs/nfsfs ?

>From the point of view of upstream, 2.6.18 is a bit old.

I can't think of any existing logging or statistics that would answer
the question; we'd probably need to add some more.

--b.