[Lustre-discuss] Lustre, NFS and mds_getattr_lock operation

[Frederik Ferner]

On our Lustre system we are seeing the following error fairly regularly, 
so far we have not had complaints from users and have not noticed any 
negative effects, but it would still be nice to understand the errors 
better. The systems reporting these errors are NFS exporters for 
subtrees of the Lustre file system.

One the Lustre client/NFS server:

May  6 14:23:09 i16-storage1 kernel: LustreError: 11-0: an error 
occurred while communicating with 172.23.68.8 at tcp. The mds_getattr_lock 
operation failed with -13
May  6 14:23:09 i16-storage1 kernel: LustreError: Skipped 10 previous 
similar messages
May  6 14:23:09 i16-storage1 kernel: LustreError: 
3515:0:(llite_nfs.c:223:ll_get_parent()) failure -13 inode 108443563 get 
parent
May  6 14:23:09 i16-storage1 kernel: LustreError: 
3515:0:(llite_nfs.c:223:ll_get_parent()) Skipped 10 previous similar 
messages

On the MDS:
May  6 14:23:08 cs04r-sc-mds01-01 kernel: LustreError: 
3595:0:(ldlm_lib.c:1643:target_send_reply_msg()) @@@ processing error 
(-13)  req at ffff81042936a000 x4806957/t0 
o34->33a488dc-5987-fee2-b810-00ff4304bf53 at NET_0x20000ac176821_UUID:0/0 
lens 312/128 e 0 to 0 dl 1273152288 ref 1 fl Interpret:/0/0 rc -13/0
May  6 14:23:08 cs04r-sc-mds01-01 kernel: LustreError: 
3595:0:(ldlm_lib.c:1643:target_send_reply_msg()) Skipped 14 previous 
similar messages

We've checked the inodes mentioned in the various messages and can't 
spot anything that would make them different from other directories 
where this does not seem to happen. Unfortunately we have so far not 
been able to reproduce it.

Does anyone know if we should worry about those messages or if we can 
safely ignore them? Or should we assume that some of our users might 
have a problem accessing data that they have just not reported? Even 
though I find that unlikely.

I've seen a thread mentioning similar messages[1] but could not find any 
conclusion.

Our MDS, OSSes and the clients involved are all running Lustre 
1.6.7.2.ddn3.5 on RHEL5. If necessary I can probably find exactly which 
patches the ddn3.5 version has applied on top of 1.6.7.2.

Kind regards,
Frederik

[1] 
http://lists.lustre.org/pipermail/lustre-discuss/2008-January/006309.html



-- 
Frederik Ferner
Computer Systems Administrator		phone: +44 1235 77 8624
Diamond Light Source Ltd.		mob:   +44 7917 08 5110
(Apologies in advance for the lines below. Some bits are a legal
requirement and I have no control over them.)