On 08/22/2012 02:07 AM, Barbara Krasovec wrote:
> Hello!
>
> Nfs4 client randomly hangs on a file or directory (for instance when
> performing df or find) and after a few seconds continues. When preforming
> strace, it hangs on getdents system call.
>
> Errors on the server side:
> Aug 19 21:29:08 host kernel: nfs: server host2 not responding, still trying
> Aug 19 21:31:17 host kernel: nfs: server host2 OK
>
> After a while the load on client and server side increases intensively, then
> system on the client side crashes. Reboot required.
>
> We use SL6.3, the same problem occurred on the following kernels:
> 2.6.32-220.17.1.el6.x86_64
> 2.6.32-279.2.1.el6.x86_64
>
> and also on:
>
> 3.5.2-1.el6.elrepo.x86_64
> 3.3.2-1.el6.elrepo.x86_64
>
> The only difference is that when we are using 3.x kernel from elrepo, the
> system crash never appears, just client hangs.
>
> Mount options:
> Flags:
> rw,relatime,vers=4.0,rsize=1048576,wsize=1048576,namlen=255,hard,noresvport,proto=tcp,port=0,timeo=600,retrans=2,sec=sys,clientaddr=IP,local_lock=none,addr=IP
>
>
> Nfs utils version:
> nfs-utils-1.2.3-15.el6_2.1.x86_64
>
> Any ideas?
> Thanks,
> Barbara

This doesn't look quite the same, but we had problems with hung tasks since 
updating to 6.3 on a couple machines.  Filed a bug here:

https://bugzilla.redhat.com/show_bug.cgi?id=851673

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Orion Poplawski
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