We have been experimenting with two new boxes with DSS providing iSCSI failover service for our five VMware ESXi 4 servers.

I am just curious about how the iSCSI failover heartbeat work and what kind of diffrent failures it detect. What I really want to know if it detects a simple failure in the iSCSI service (for example if the iSCSI target deamon craches) or if it only detects when the whole box goes down and stops responding to ping.

In other words, does the seconday DSS server check that the iSCSI target service on the primary servers if functional, or does it only monitor if it responds to heartbeat or ping?

To test, I am thinking about placing the primary DSS server behind a firewall allowing all traffic, and put the secondary box and the ESXi servers on the other side. If I then block port 3260 (iscsi service) to the primary DSS server, will the seconday DSS server see that and initiate a failover?

Am I making any sense at all? ;-)