On Wed, 06 Oct 2010 21:42:57 -0700, Chris Hobbs chobbs@nhusd.k12.ca.us wrote:
For documentation's sake, here's what I've done so far:
I do have one more idea I'll throw out there. Everything I've got here is virtual. I only have the one Dovecot/Postfix server running now, and the impression I get from you all is that that should be adequate for my load. What would the collective opinion be of simply removing the NFS server altogether and mounting the virtual disk holding my messages directly to the dovecot server? I give up the ability to have a failover dovecot/postfix server, which was my motivation for using NFS in the first place, but a usable system probably trumps a redundant one.
Chris
I have done some tests here that shows that NFS is a major overhead compared to local filesystem on iSCSI volume. I have tested only NFS4 with linux clients and server. Finally we went with a couple of mails servers that mount OCFS2 shared volume - this setup also has some drawbacks in terms of complexity.
You also could achieve redundant mail system with local fs (XFS for example) over iSCSI volume - one server will be standby and will mount the volume and bring up a floating IP if primary goes down. You could automate such a setup with heartbeat/pacemaker or other cluster manager. Though, in such a setup you could not load-balance if you are serving only one mail-domain.
Best regards
-- Luben Karavelov Research and development Spectrum Net JSC
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