Dear All, Scenario: I am facing a unique issue as below. I have two physical machines installed with a windows beta virtualization env. on them. There is one centos 5.2 virtual server running on each physical machine. There is a SAN (IBM) partition provided to the virtualized servers by the host Windows OS on both physical machines. The partition is formated in ext3 Both the virtualized Centos servers are linked using heartbeat so that any of the server goes down the other server will take on the resources (Namely a floating IP and SAN storage) and start the services so that there is minimal interruption in services during hardware failure of one server. This is similar to heartbeat with drbd sans drbd. We have imap user data mounted on the system as since we had a SAN storage didnt opt for internal Storage or drbd structure. Graphical Representation is attached for elaboration. Problem: The problem is that during the fail over testings we found that the ext3 partition became read only during transition from one server to other server. What i want to know is 1. if attached scenario is feasible where in during failover occurs the other server mounts the SAN storage and mailbox server is available at all time. 2. What happens when one server has network issue but has not unmounted the SAN ? Is this the case why probably my partition becomes read only? regards, Ashay.