[Linux-cluster] optimising DLM speed?
Alan Brown
ajb2 at mssl.ucl.ac.uk
Thu Feb 24 23:14:35 UTC 2011
On 24/02/11 22:40, Scooter Morris wrote:
> Hi all. After two tries, we've modified our cluster so that all nodes
> have increased their dlm hash table sizes to 1024. Initially, I put
> the echos in /etc/init.d/gfs2, but it turns out that /etc/init.d/gfs2
> is sort of a no-op: /etc/init.d/netfs mounts the gfs2 filesystems
> before /etc/init.d/gfs2 is ever called, so the echos need to be before
> netfs.
>
I created a new init.d script to apply the values immediately after cman
is started - see attached files.
> At any rate, we have noticed a significant perceived improvement in
> overall performance of the systems. Where before, it was common to
> see imap process in D wait -- sometimes hanging for long periods of
> time -- we have not seen that at all since updating the hash table
> size. So far, so good!
How much ram have you got and which version of gfs2 are you running?
vermagic: 2.6.18-238.1.1.el5 SMP mod_unload gcc-4.1
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