Does kvm support live migration with non-shared storage?

Issue

• Does kvm support live migration with non-shared storage?

Live migration with non-shared storage in RHEL6/RHEV3.* is a deprecated functionality, but under certain circunstances and with some limitations, it works fine. In RHEL7, this feature has been disabled.

A more modern and robust implementation of this feature, using NBD and drive_mirror, has been implemented upstream and is planned for a future release of RHEV.

Using virsh, the syntax to perform live migration with non-shared storage via virsh should be:

# virsh migrate --live guest-vm qemu+ssh://host2/system --copy-storage-all

Given the limitations of the current implementation, the migration started with the command above may never finish (converge). Besides, in old versions of the packages and in RHEL7, the command above may return an error like:

error: command 'migrate' doesn't support option --copy-storage-all