LARGE single-system Cyrus installs?

[Alain Spineux]

On Nov 8, 2007 4:56 PM, Dan White <dwhite at olp.net> wrote:
> Michael D. Sofka wrote:
> > On Thursday 04 October 2007 07:32:52 pm Rob Mueller wrote:
> >> 4. Lots of other little things
> >>
> >> a) putting the proc dir on tmpfs is a good idea
> >> b) make sure you have the right filesystem (on linux, reiserfs is much
> >> better than ext3 even with ext3s dir hashing) and journaling modes
> >
> > On a Murder front-end server, could the tls_sessions.db be put on a
> > tmpfs?  What about mailboxes.db, since the murder master would have
> > the master copy anyway.  (This would slowdown startup in the case
> > of the system loosing power.  But, ``the front end servers can be
> > considered 'dataless' '' according to: http://cyrusimap.web.cmu.edu/ag.html)
> >
> > We have a Murder Aggregate with two front-end and three back-end
> > servers, and the master.   I've noticed the front-end servers are a little
> > IO bound.  They each have a single disk, and I discovered that half
> > of the IO wait went away when I buffered the cyrus.log file in syslogd.
> > But, they still show an average of 5-6% IO Wait for processes.
> >
> > Moving imap/proc to tmpfs, however, had a negligible effect.
> >
> >  I'll spec a two-disk system when new front-end's are ordered,
> > but that would only split system from cyrus.   Would it make more
> > sense (and, more importantly, would it work and not foobar us) to order
> > a machine with more memory, and put configdirectory: on tmpfs?  (With
> > the possible exception of the db snapshots and mboxlist backups.)
> >
> > Mike
> >
>
> Hi Mike,
>
> While reviewing this thread for optimization ideas, I came across
> your comment about buffering the cyrus.log in syslogd. Could you
> explain what you did to configure that?

Syslogd flush every write to disk
You can ask syslog to omit syncing file by prefixing the name of your
file by "-".
Look the man page for more.

Regards


>
> Thanks,
> - Dan White
> BTC Broadband
>
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-- 
Alain Spineux
aspineux gmail com
May the sources be with you