You should of course always keep the kernel, and other packages, updated on your server. If you are using quotas rebooting openvz can take a while to bring back all VZ if there are a lot of files on the server.
Ksplice is a worthwhile thing for most people, we have been using it for awhile and like it.
John W, CISSP, C|EH
MS Information Security and Assurance ITEagleEye.com - Server Administration and Security Yawig.com - Managed VPS and Dedicated Servers with VIP Service
Thanks you all for the suggestions.
I have updated on my new node where i have few containers, but before i update on my old node where i have many virtual containers let me ask you did you ever face an issue with the node or container after kernel or other software update ??