Re: NFS4 in combination with root over NFS3, hangs and deadlocks

[Anton Starikov <ant.starikov@gmail.com>]

On Mar 30, 2010, at 9:00 PM, Chuck Lever wrote:

> On 03/30/2010 02:30 PM, Anton Starikov wrote:
>> If it is already resolved problem, can someone point me into direction of particular patch?
> 
> As far as I know NFSv4 is known not to work with an NFSv3 root, in any kernel.


But NFS4-root (does it work finally?) isn't always desirable solution. Especially if different OSes used for client/server.

And it seems that generally it works, just some deadlock occurs, probably related to caching of some credentials.

Anton,

>> Anton.
>> 
>> 
>> On Mar 29, 2010, at 5:14 PM, Anton Starikov wrote:
>> 
>>> Hi,
>>> 
>>> Early (year ago and recently) I reported about my faults in getting working NFS4 mounts (primary automounting /home) with system booted with NFSv3-root. It always used to silently hang nodes with zero output in the logs. It was definitely client issue (I tried it with different versions of linux and solaris servers)
>>> 
>>> Although I can't get simple and reproducible test-case, because hangs appears randomly, it can happen in 1hour, it can happen in 5 days, but it always will happen after some time. But this time I got some some improvement.
>>> 
>>> With 2.6.32.9-70.fc12.x86_64 kernel and fresh nfs-utils from Fedora-12, after NFS4 mounts hangs, NFS3 mounts and node itself still continue to work, which gives chance to investigate problem.
>>> 
>>> Can you give me instruction how to collect all necessary information to figure out where the bug is?
>>> 
>>> As starting point I will attach output of echo "t">  sysrq-trigge, list of NFS mounts.
>>> 
>>> Thanks,
>>> Anton.
>>> 
>>> # cat /proc/mounts | grep nfs
>>> 172.19.8.1:/export/share/cluster/fedora-root / nfs ro,relatime,vers=3,rsize=32768,wsize=32768,namlen=255,hard,nolock,proto=udp,port=65535,timeo=7,retrans=3,sec=sys,mountport=65535,addr=172.19.8.1 0 0
>>> none /var/lib/nfs tmpfs rw,relatime 0 0
>>> sunrpc /var/lib/nfs/rpc_pipefs rpc_pipefs rw,relatime 0 0
>>> 172.19.8.1:/export/share/cluster/admin /root nfs rw,noatime,vers=3,rsize=1048576,wsize=1048576,namlen=255,hard,nolock,noacl,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=172.19.8.1,mountvers=3,mountport=44114,mountproto=tcp,addr=172.19.8.1 0 0
>>> 172.19.8.1:/export/share/cluster/checkpoint /mnt/checkpoint nfs rw,noatime,vers=3,rsize=1048576,wsize=1048576,namlen=255,hard,noacl,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=172.19.8.1,mountvers=3,mountport=52574,mountproto=udp,addr=172.19.8.1 0 0
>>> 172.19.8.1:/export/share/software /software nfs rw,noatime,vers=3,rsize=1048576,wsize=1048576,namlen=255,hard,nolock,noacl,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=172.19.8.1,mountvers=3,mountport=44114,mountproto=tcp,addr=172.19.8.1 0 0
>>> 172.19.8.1:/export/share/cluster/torque /var/torque nfs rw,noatime,vers=3,rsize=1048576,wsize=1048576,namlen=255,hard,nolock,noacl,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=172.19.8.1,mountvers=3,mountport=44114,mountproto=tcp,addr=172.19.8.1 0 0
>>> 172.19.8.1:/export/share/common/ /common nfs4 rw,noatime,vers=4,rsize=1048576,wsize=1048576,namlen=255,hard,proto=tcp,port=0,timeo=600,retrans=2,sec=sys,clientaddr=172.19.8.133,addr=172.19.8.1 0 0
>>> 172.19.8.1:/export/home/alfons/ /home/alfons nfs4 rw,relatime,vers=4,rsize=1048576,wsize=1048576,namlen=255,hard,proto=tcp,port=0,timeo=600,retrans=2,sec=sys,clientaddr=172.19.8.133,addr=172.19.8.1 0 0
>>> 
>>> <log1.txt.gz>
>>> 
>> 
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> 
> 
> -- 
> chuck[dot]lever[at]oracle[dot]com