VM's shows status unknown and there are 2 libvirtd daemon running

This is the process to avoid any shutdown of VMs: 1) Disable power management for this host. Do this from the webUI by opening the Edit menu for the host, opening the Power Management tab, uncheck "Enable Power Management" and then click ok. 2) On the host, kill the two libvirt processes.

ps -ef|grep libvirt|grep listen 3) Start libvirtd again, note that this requires initctl instead of service on RHEL 6: # initctl start libvirtd 4) Wait about 60 seconds and then try the migration again.