I've got a cluster with 84 Openstack Essex compute nodes, one of which decided to pine for the fjords about 2 hours ago, with 8 running instances on it.
The instances are all running off qcow2 disks on an NFS share, so the disk images are still available.
nova live-migration only seems capable of migrating a running instance from one functioning node to another.
What I want is to 'migrate' the dead instances from the dead compute node to any of the live compute nodes. The fact that the instances will be rebooted (and will have to fsck on boot) doesn't really matter - it's better than losing them completely.
Before I start acting on thoughts about messing with virsh and hacking nova's mysql database directly, does anyone know of any tool or documented procedure for this kind of 'dead-migration'?