[Linux-cluster] rhel 6.1 gfs2 performance tests

[Steven Whitehouse]

Hi,

On Fri, 2011-07-22 at 12:08 +0200, Jordi Renye wrote:
> Hi,
> 
> We have configured redhat cluster RHEL 6.1  with two nodes.
> We have seen that performance of GFS2 on writing  is
> half of ext3 partition.
> 
> For example, time of commands:
> 
> time cp -Rp /usr /gfs2partition/usr
> 0.681u 47.082s 7:01.80 11.3%    0+0k 561264+2994832io 0pf+0w
> 
> whereas
> 
>   cp -R /usr /ext3partition/usr
> 0.543u 24.041s 4:16.86 9.5%     0+0k 2728584+3166184io 2pf+0w
> 
> With  ping_pong tool from Samba.org we've got next results:
> 
> Los resultados son los siguientes:
> 
> ping_pong /gfs2partition/pingpongtestfile 3
> 1582 locks/sec
> 
> With ping_pong test r/w:
> 
> ping_pong -rw /gfs2partition/pingpongtestfile 3
> data increment = 2
> 4 locks/sec
> 
> Do you think we can get better performance? Do you think
> are "normal" and "good" results ?
> 
> Which recommendations do you tell us to get better performance?
> 
> For example, we don't have a heartbeat network exclusively, but
> we have only one networks interface for application network and cluster 
> network.
> Could we get better performance with one dedicated cluster network( for 
> dlm,heartbeath,...).
> 
> Thanks in advanced,
> 
It depends what you are trying to optimise for... what is the actual
application that you want to run?

cp doesn't use fcntl locks to the best of my knowledge, so I doubt that
will have any particular effect on the performance. Also it would be
quite unusual for fcntl locks to have any effect on the performance of
the fs as a whole.

Usually the most important factor is how the workload is balances
between nodes. Also, did you mount with noatime, nodiratime?

Steve.