21.2. Configuring guest live migration

This section covers offline migration of Xen guests to other servers running Red Hat Enterprise Linux. Further, migration is performed in an offline method (using the xm migrate command). Live migration can be done from the same command. However there are some additional modifications that you must do to the xend-config configuration file. This example identifies the entries that you must modify to ensure a successful migration:
(xend-relocation-server yes)
The default for this parameter is 'no', which keeps the relocation/migration server deactivated (unless on a trusted network) and the domain virtual memory is exchanged in raw form without encryption.
(xend-relocation-port 8002)
This parameter sets the port that xend uses for migration. Use this value unless your network environment requires a custom value. Remove the comment symbol to enable it.
(xend-relocation-address )
This parameter is the address that listens for relocation socket connections, after you enable the xend-relocation-server . The Xen hypervisor only listens for migration network traffic on the specified interface.
(xend-relocation-hosts-allow )
This parameter controls the host that communicates with the relocation port. If the value is empty, then all incoming connections are allowed. You must change this to a space-separated sequences of regular expressions, for example: 
(xend-relocation-hosts-allow- '^localhost\\.localdomain$' )>
Accepted values included fully-qualified domain names, IP addresses or space separated regular expressions.
After configuring, reboot the host to load new settings.