The ESX hosts failed to connect over the VMotion network
Migration [167894541:1376412154364871] failed to connect to remote host <10.1.221.12> from host <10.1.222.13>: Network unreachable
The vMotion failed because the destination host did not receive data from the source host on the vMotion network. Please check your vMotion network settings and physical network configuration and ensure they are correct.
The SANs are on a private network (the IP's above), connected via iSCSI, and not connected to the main network at all We've never had any issues with them in that setup.
So you are using the iSCSI vmkernel network as your vMotion network as well? If yes this would be multi homing and not supported for that exact reason you seem to be experiencing.
What is the subnet mask for those 2 networks mentioned above, are those at least in the same subnet or are you trying to get a routed vMotion working? (which would be unsupported as well).
Ideas?
Get into a supported configuration or post more details on your network setup please.
For DRS we would need to see your settings, is it set to automatic, what is the active memory usage of the VMs, not the consumed, means is the cluster really imbalanced. Do you get recommendations when you manually invoke DRS?