Oh and one final question, how does GlusterFS handle split-brain? Let's
say somehow the replication link became broken, but both Postfix servers
continued to operate...
This is documentation from 2.x series of GlusterFS but it still applies to 3.x:
http://www.gluster.com/community/documentation/index.php/Understanding_AFR_Translator
Major point is that GlusterFS is NOT another file system. GlusterFS uses a disk
based backend and relies heavily on the underlying filesystem extended
attributes for handling which file is more recent on one brick over another
when performing a self heal after a split brain condition.
Maybe this isn't really too much of an issue in mail delivery, as find
aren’t usually modified, are they?
I may split up the servers though to reduce split brain. As if one
glusterfs server goes down, no mail server would be able to access it
