In preparing for upgrading our lab Private Cloud Appliance (PCA) to the new release 2.3.2 (more on that later, but read here first) I remembered that we had already introduced a feature called Storage Live Migration (SLM). That lets you live migrate a VM from one server to another, even when its virtual disks and metadata are on a local file system repository instead of the typical shared SAN or NAS storage resource which would be accessible to both source and target servers.
SLM came with Oracle VM 3.4.2, which is part of PCA 2.3.1 which my lab was already running. Why not try it?
This could be handy on PCA, since every compute node (Oracle VM Server host) on the Private Cloud Appliance includes a disk repository (named ovcacnXXr1-localfsrepo where XX matches the host name) with about 1TB of capacity, which can be used to augment the internal ZFS storage array and the recommended external storage. With SLM, I could have VMs on local disk storage but still move them to other servers while running.
I created a VM on one of the compute nodes, using it's local storage repository. When I had it up and running. I went to live migrate it and selected the option to migrate it and its storage.
I then moved to the next screen and picked the destination host:
I clicked "Finish" and that kicked off the migration. No muss, no fuss - it Just Worked.
Live migration is a widely used and useful administrative procedure that moves a running VM from one server to another without loss of service. It's intended for load balancing VMs across a pool or server or to evacuate a server for maintenance, Storage Live Migration enhances this feature by permitting its use when virtual machine contents are on local storage rather than disk storage available to all the server. The Private Cloud Appliance has had this capability since PCA 2.3.1 was released last summer, making it an even more agile solution and permitting use of each server's storage capacity.