We are running into an issue here where the Cluster-Shared Volume attached to our Hyper-V 2012 R2 cluster is being dropped off / faulted with the slightest interruption from the iSCSI SAN connection it's using. This is, of course, a problem as it causes all the VMs to crash or shutdown.
The interruptions in the iSCSI SAN connection happen when the primary SAN node fails over to its replica. There are about 10-15 seconds of downtime before the secondary picks up. We are using a FreeBSD + ZFS based solution in conjunction with HAST + CARP to provide high availability storage.
The failover works when a non-clustered iSCSI LUN is mounted on the Windows side, for example, a normal connection with the initiator. The I/O simply gets paused until the connection is reestablished. I expected the same behavior with the CSV but alas, it seems to be very picky about I/O timeouts.
Is there a way to lengthen the CSV timeout, or perhaps some other fix for this issue?