[ovirt-users] Guests Not Responding

For some reason today my guests have decided to go into a not responding state according to the WebUI. I am running a hosted engine environment with one physical host. I can power them down, then run them and they show good for a few seconds, then go to not responding - the question marks. I can connect to them via ssh but functions such as removing a snapshot fail on the finalizing step. The hosted-engine --vm-status shows good and healthy. The vdsm log on the says the guest is up. The messages log show 11 guests active which is correct. I'm at a loss as to where to look next. I've found some threads which indicated someone deleted live snapshots and things got fixed so I'm attempting to delete some snapshots but that doesn't help. By the way - what is the difference between a snapshot created via Create on a VM Snapshots list and a live snapshot? Any help is appreciated. Thanks.