How redhat HA suite works for Postgres(in terms of postgres data)

Environment
Production = 2 nodes(node1 and node2)
OS = rhel 7.3
HA product = RHCS(redhat add-on)
Postgres = 9.6
Shared SAN storage = available

"My concept"
At production site: Node1(active) will be replicating postgres data to Node2(passive) so in case fail-over occurs from node1 to node2 then a copy of postgres data will be available on node2 ?
OR
when Node1 is active (and shared san storage is mounted on node1 where postgres data exist) and in case fail-over occurs from node1 to node2 then node2 will be using postgres data from SAN