Hi Tim,
Yes, so far we've been successfully running VMs in hyper-v clusters which are stored on a iscsi lun in open-e DSS V6 SAN which is in active/passive failover with another open-e SAN. We have several implementations of this. Lun is a CSV for the hyper-v cluster and we use MPIO for two front-end cluster hosts with two iscsi switches, although it works fine with only one switch too. The failover works without VMs crashing - both failover and failback - it has been working for the past couple of years now. It was a bit of a trick to get this to work at first, but once configured right it ticks on just fine.
I am not sure if that has been a long standing issue with V6- I certainly don't remember seeing any posts where this has been confirmed - but we are only having problems with this since the upgrade to V7.