Containers can be migrated via command line (windows)
Syntax
Simple format
vzmigrate -f container_ID -A Destinationserver_IP -U administrator -P password
More functions
vzmigrate -f 175 -A {DestinationHNaddress} -U {Destination Node Administrative Username} -P {Password for account with rights on Destination Node} -r yes
The -r yes at the end of the command removes the container from the source node after successful migration, it is optional.
Example
vzmigrate -f 100 -A 11.11.11.12 -U administrator -P password
For more information refer
http://forum.parallels.com/pda/index.php/t-89784.html