Yesterday was a very long night, I didn’t leave work till 9:30pm. It was because I was trying to figure out how to live migrate a cloud server from one hypervisor to another with a targeted destination. This ensures that any customer using the openstack for cloud reaches a hypervisor in the same cell:

 
supernova lon live-migration --block-migrate uuidgoeshere c-10-1-1-1

Where ‘uuidgoeshere’ is the uuid of the server to migrate, and c-10-1-1-1 is the target of the hypervisor. It was as simple as that, during the live migration, only a few packets are dropped by the server. This ensures very good continuity and minimizes the disruption that would have otherwise been experienced had you imaged, and then rebuilt the server that way! In our case, the lon part is just the configuration file used by supernova. supernova is a wrapper for nova.