remote access via NFS

Hello,
I need to access PostgreSQL data created by one Postmaster from second
Postmaster running on another host. Both Postmasters will access data via
NFS.
What configuration setting should be created in postgresql.conf or/and what
config parameters should be used as a command line options to the
postmaster?
I understand that sharing a DB via NFS is not good idea, but still .. I
need to test such configuration so that in the event that the first host
goes down, the second host can act as a backup and continue using the same
data files.

Thank you in advance for your advice,
Eugene