[Lustre-discuss] need help debuggin an access permission problem

[Ashley Pittman]

On 23 Sep 2010, at 10:46, Tina Friedrich wrote:

> Hello List,
> 
> I'm after debugging hints...
> 
> I have a couple of users that intermittently get I/O errors when trying 
> to ls a directory (as in, within half an hour, works -> doesn't work -> 
> works...).
> 
> Users/groups are kept in ldap; as far as I can see/check, the ldap 
> information is consistend everywhere (i.e. no replication failure or 
> anything).
> 
> I am trying to figure out what is going on here/where this is going 
> wrong. Can someone give me a hint on how to debug this? Specifically, 
> how does the MDS look up this sort of information, could there be a 
> 'list too long' type of error involved, something like that?

Could you give an indication as to the number of files in the directory concerned?  What is the full ls command issued (allowing for shell aliases) and in the case where it works is there a large variation in the time it takes when it does work?

In terms of debugging it I'd say the log files for the client in question and the MDS would be the most likely place to start.

Ashley,

-- 

Ashley Pittman, Bath, UK.

Padb - A parallel job inspection tool for cluster computing
http://padb.pittman.org.uk