BUG #5513: High availability with Postgres

The following bug has been logged online:

Bug reference:      5513
Logged by:          Elior
Email address:      elior.s@correlix.com
PostgreSQL version: 8.3.1
Operating system:   Centos
Description:        High availability with Postgres
Details:

Hello,

My company looking for some solution for High availability with Postgres.

Our optional solution is as follows :
Two DB servers will be using a common external storage (with raid). Both
servers are going to use the same DB files on the storage (as
active/passive)

Now I'm trying to understand how Postgres can work with this configuration.
I.e :

DB_server1 crashed, so we want to start DB_server2 using same files.
Is it possible ?

Regards,
Elior