[Ocfs2-users] poor 2 node performance

[Wim Coekaerts]

Hi Ian

most of the multinode stuff is very much in flux right now (kurt is
basically rewriting it).  killing syslogd would definitely help ;) but
it won't be the silver bullet. anyay yeah multinode just right now
sucks, but the new dlm/net/nm stuff will be plugged in soon

Wim

On Sun, Oct 17, 2004 at 10:11:43PM +0100, Ian Pratt wrote:
> 
> Hi,
> 
> I've been setting ocfs2 up on a two node 'cluster', using gnbd
> (network block device) to talk to a shared disk on a third node.
> 
> build/install was very straightforward and I have the file system
> mounted on both nodes just fine. However, I've been rather
> disappointed by the performance: With just one node actively
> using the fs (but with the other mounted) I'm finding that file
> system operations are running *very* slowly -- a linux kernel
> build takes 5 times longer, with the system blocked on IO most of
> the time. 
> 
> Looking at the node that is supposedly quiescent, I see that
> kernel thread "events/0" is burning 100% of the CPU. Sure enough,
> syslog is filling up rapidly with messages of the form:
> 
> Oct 17 22:01:13 breakout-0 kernel: process_vote: type: MODIFY, lockid: 2751426560, action: (11) <NULL>, num_ident: 1, alive: 1, write: 0, change2719924224, node=1, seqnum=551559, response=1
> 
> I guess I could disable the logging, but, I'm still rather
> surprised about the amount of communication between the nodes.
> Is this normal?  I guess I was hoping that ocfs2 used some kind
> of hierarchical read/write/existence locking on fs subtrees.
> 
> Performance with just a single node mounted is perfectly
> respectable.
> 
> Any suggestions?
> 
> Thanks,
> Ian
> 
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