[Linux-cluster] GFS2 locking issues

[Abhijith Das]

Dennis,

You seem to be running plock_rate_limit=100 that limits the number of
plocks/sec to 100 to avoid network flooding due to plocks.

Setting this as <gfs_controld plock_rate_limit="0"/> in cluster.conf
should give you better plock performance.

Hope this helps,
Thanks!
--Abhi

Dennis B. Hopp wrote:
> We have a three node nfs/samba cluster that we seem to be having very
> poor performance on GFS2.  We have a samba share that is acting as a
> disk to disk backup share for Backup Exec and during the backup
> process the load on the server will go through the roof until the
> network requests timeout and the backup job fails.
>
> I downloaded the ping_pong utility and ran it and seem to be getting
> terrible performance:
>
> [root at sc2 ~]# ./ping_ping /mnt/backup/test.dat 4
>        97 locks/sec
>
> The results are the same on all three nodes.
>
> I can't seem to figure out why this is so bad.  Some additional information:
>
> [root at sc2 ~]# gfs2_tool gettune /mnt/backup
> new_files_directio = 0
> new_files_jdata = 0
> quota_scale = 1.0000   (1, 1)
> logd_secs = 1
> recoverd_secs = 60
> statfs_quantum = 30
> stall_secs = 600
> quota_cache_secs = 300
> quota_simul_sync = 64
> statfs_slow = 0
> complain_secs = 10
> max_readahead = 262144
> quota_quantum = 60
> quota_warn_period = 10
> jindex_refresh_secs = 60
> log_flush_secs = 60
> incore_log_blocks = 1024
> demote_secs = 600
>
> [root at sc2 ~]# gfs2_tool getargs /mnt/backup
> data 2
> suiddir 0
> quota 0
> posix_acl 1
> num_glockd 1
> upgrade 0
> debug 0
> localflocks 0
> localcaching 0
> ignore_local_fs 0
> spectator 0
> hostdata jid=0:id=262146:first=0
> locktable
> lockproto lock_dlm
>
>        97 locks/sec
> [root at sc2 ~]# rpm -qa | grep gfs
> kmod-gfs-0.1.31-3.el5
> gfs-utils-0.1.18-1.el5
> gfs2-utils-0.1.53-1.el5_3.3
>
> [root at sc2 ~]# uname -r
> 2.6.18-128.1.10.el5
>
> Thanks,
>
> --Dennis
>
>
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