Multi-server but small scale

[Daniel Miller]

I have a small but critical server that supports our group.  As a single 
server - it's obviously a single-point-of-failure for lots of things.  
As I just experienced...again.  It was a lot more fun building systems 
from components when I was younger...

Previously 3rd-party hosted solutions didn't look attractive for several 
reasons...but I'm seeing prices now for cloud virtual machines that are 
stupid cheap.  Even if they wind up being limited speed & availability - 
it would seem they'd be a lot better than nothing!

So I'm considering having at least one backup server for various 
services - obviously that includes mail.  So now I have to wonder about 
the backend.  And while I think I'm reasonably current with networked 
file systems (not distributed or cluster) I haven't played with 
replication for a quite a while.

For this particular usage (I'm envisioning two servers total) - is there 
a need/reason to use any form of networked/distributed/cluster file 
storage?  Or would this be accomplished via "pure" Dovecot - dsync 
replication would keep things updated between the servers and director 
would handle the connections?  So with identically configured SMTP 
servers, passing to the local LMTP agents, the file system would be 
"purely local" with no NFS or other interconnection?

-- 
Daniel