I am working on setting up a Hyper-V cluster with two nodes for failover/high availability. I think I have a pretty basic understanding of what is needed to set this up so far, but I had a question. Let's say I have the two nodes setup, with dual switches for multipath and an iSCSI SAN for storage of the VMs. From my understanding both nodes would use the VMs that are on the SAN (not simultaneously, but one node would take over should the other node go down). Let's say that one of the VMs is running Windows Server 2008 and while doing security patches, etc. there is a corruption/issue with the OS. Obviously, this would effect either node since they are using the same file. I suppose that one would have to resort to restoring from backup at that point, but doesn't that make the failover/high availabilty pointless to some extent? Perhaps there is something that I am missing and would appreciate any insight on how this should be handled properly. Thanks!