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

Anton Starikov
2010-03-31T00:09:23Z

I'm not an expert in kernel debugging, but I think hang happens in rpcauth_lookup_credcache

On Mar 30, 2010, at 10:59 PM, Anton Starikov wrote:

> Then it isn't normal.
> Diskless setup is limited by old NFS3 for non-root partition, which isn't nice.
> no proper ACL, no delegations.
>
>
> On Mar 30, 2010, at 9:27 PM, Chuck Lever wrote:
>
>> On 03/30/2010 03:11 PM, Anton Starikov wrote:
>>> 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.
>>
>> No, NFSv4 root is known to have problems, and is unsupported, as far as I know.
>>
>>> 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
>>>
>>
>>
>> --
>> chuck[dot]lever[at]oracle[dot]com
>