[Dovecot] Clustering dovecot?

[dovecot at corwyn.net]

At 01:49 PM 5/27/2009, Rick Romero wrote:

>>But what it sounds like you're saying is that there's no good way to
>>run dovecot so that if the single server it's on fails I can keep
>>service availability?
>
>If you have 2 dovecot servers with your mailboxes stored on a SAN
>(over NFS), you can front your 2 dovecot machines with a load balancer
>like UltraMonkey (LHA/Heartbeat).

Would this mean I would configure two identical dovecot systems, and 
point them both at the same SAN space? (so instead of having a 
"clustered" environment both instances of dovecot are just using 
shared filespace?)  Isn't there a risk there of both dovecot 
instances writing a file/email with the same filename?

(and I presume also have my user mysql config also stored and shared 
on the SAN between the two servers?).

RickS