Recently had a OVS root file system fill up due to a run away iSCSI process (and I don’t even use iSCSI…). This had a side affect of affecting almost any task that needed to interact with the Xen hypervisor (status, start, stop, etc).
Once I had worked this out and cleaned up the logs to gain space back, I had one VM which was in a very upset state and couldn’t be started, shutdown, anything. I was getting a “Error: Acquire running lock failed: 256”.
I Googled this, and lots of people suggested I delete the OVS database, but that is a big hassle (been there before).
I worked around this problem, with the following:
force a xm destroy of the VM on the command line of the host where the machine was 1⁄2 running. delete the VM (but not the config or disk) in OVM Import the VM Start it. By deleting it and importing the VM I avoided a lot of hassle. Hope this helps someone else.