Multiple databases

Hiya,

We're looking into ways to cluster our database servers and
shared storage.  Here's the low-down on our servers... all
run RedHat 7.3 with a few patches and are dual PIII 1.4GHz,
2GB, mirrored internal 36, Qlogic 2310 HBA to a LUN on our
Hitachi.  PostgreSQL 7.3.3 is installed from source and the
one that came with RH has been removed.

There are currently 3 of these servers and each are designed
to run 1 instance of PostgreSQL with 10-20 databases of varying
size from 5 to 20GB.  I have PostgreSQL pretty well tweaked to
maximize memory so I'm hesitant to have a 2nd instance running
on the server in the case of a failover.

This is what I'm curious about.

Server A has it's databases under /pg/dataA and Server B has
it's databases under /pg/dataB both are different LUN's on our
SAN.  Should Server A choke, Server B should fsck /pg/dataA
and mount it locally.  At this point it needs to either

  (1) start a new instance of PostgreSQL listening on 5432/tcp
      but bound to a different IP
or
  (2) the current PostgreSQL "imports" the databases under
      /pg/dataA

Each have their good points and problematic issues.

Thoughts?

Greg

--
Greg Spiegelberg
  Sr. Product Development Engineer
  Cranel, Incorporated.
  Phone: 614.318.4314
  Fax:   614.431.8388
  Email: gspiegelberg@Cranel.com
Cranel. Technology. Integrity. Focus.