Question 2
<p>
Start up one postmaster, but create two databases:
<pre>
createdb acs1
createdb acs2
</pre>
Then do the obvious thing in your datasource statements for the two virtual servers.
<p>
The only reason to start two postmasters would be to listen on two separate IPs (or ports), or to vary the resources used by each ACS installation (shared buffer pool, etc). The last is probably not a good reason, I think you'd always be better off with a single postmaster and let it use ample shared buffer memory and give it a big limit for sorts and heap joins (Postgres spills to disk if this limit is overrun).
<p>
OK, I can hear the next question, and yes, I should probably write up a short document called "PG configuration for ACS/pg newbies" :)
