[Dovecot] Redundant shared mail store?

[Jasper Bryant-Greene]

Hi guys

I'm about to embark on a project replacing a legacy single mail server
running proprietary software with a cluster of Dovecot servers. We
clearly need a shared mail store for these servers, but we are not happy
with simply using a server running NFS as this becomes a single point of
failure.

What have other people used? AFAICT our options are:

	* A shared block device (Fibre Channel, iSCSI, ATAoE etc) running GFS
or similar to allow multiple servers to access it concurrently

	* Two or more NFS units, either with built-in support for replication
of FS changes and failover, or with scripts for achieving this functionality

I prefer option 1, although it's expensive. What have other people used?
Do we have other options?

TIA
-- 
Jasper Bryant-Greene
Director
Album Limited

jasper at albumltd.co.nz
+64 21 708 334 / 0800 425 286
http://www.albumltd.co.nz/