There are several limitations to consider when preparing for and performing a live migration. One of them is that no operations can be performed on a virtual machine that is being live migrated. Still, you can use virsh on the source compute node to interact with the virtual machine. Specifically:
1. View the current state of the live migration:
# virsh domjobinfo domain Time elapsed 110110 ms Data processed 100.500 GiB Data remaining 25.500 GiB ...[output truncated]...
Replace domain with the name, numeric ID or UUID of the virtual machine which is being migrated.
2. Cancel the migration:
# virsh domjobabort domain
3. Pause the virtual machine:
# virsh suspend domain
Virtual Machines under heavy memory load are hard to live migrate. In such cases you can set maximum down time. To do this on a live migration which is not in progress, use QEMU:
# virsh qemu-monitor-command --hmp domain migrate_set_downtime time_in_seconds
To set maximum down time on a live migration which is in progress, use libvirt:
# virsh migrate-setmaxdowntime domain time_in_milliseconds