Having been completely clueless about Openvz three days ago I first created a dummy container based on the same distribution I wanted to migrate. This helped me greatly to understand what was needed and also allowed to use the dummy as a template for /dev and the conf file. Disregarding the time to setup the host system the actual migration from the physical machine with tar ball took me two hours and the migrated container started up on second attempt after first complaining about disk size. I increased that and it runs. I am very impressed by the ease of it all.