[Linux-cluster] GFS Performance Problems (RHEL5)

[Paul Risenhoover]

I'm guessing my problem has to do with this:


Paul Risenhoover wrote:
> Hi All,
>
> I am experiencing some substantial performance problems on my RHEL 5 
> server running GFS.  The specific symptom that I'm seeing is that the 
> file system will hang for anywhere from 5 to 45 seconds on occasion.  
> When this happens it stalls all processes that are attempting to 
> access the file system (ie, "ls -l") such that even a ctrl-break can't 
> stop it.
>
> It also appears that gfs_scand is working extremely hard.  It runs at 
> 7-10% CPU almost constantly.  I did some research on this and 
> discovered a discussion about cluster locking in relation to 
> directories with large numbers of files, and believe it might be 
> related.  I've got some directories with 5000+ files.  However, I get 
> the stalling behavior even when nothing is accessing those particular 
> directories.
>
> I also tried some tuning some of the parameters:
>
> gfs_tool settune /mnt/promise demote_secs 10
> gfs_tool settune /mnt/promise scand_secs 2
> gfs_tool settune /mnt/promise/ reclaim_limit 1000
>
> But this doesn't appear to have done much.    Does anybody have some 
> thoughts on how I might resolve this?
>
> Paul
>
> -- 
> Linux-cluster mailing list
> Linux-cluster at redhat.com
> https://www.redhat.com/mailman/listinfo/linux-cluster