:: What is vzdump
Vzdump is a utility to make consistent snapshots of running OpenVZ containers (and KVM virtual machines if you are using Proxmox VE). It basically creates a tar archive of the container’s private area, which also includes the CT configuration files.
 
:: How to backup OpenVZ Container
+ backup one of VPS

vzdump --compress --suspend VEID

or

vzdump --compress --stop VEID

+ backup all of vps

vzdump --compress --suspend --all

or

vzdump --compress --stop --all

all backup files will saving on /vz/dump/, if you want save to another directory, you can add –dumpdir

vzdump --compress --dumpdir /backup --suspend --all

 

:: How to restore OpenVZ dump files

vzrestore /vz/dump/vzdump-VEID.tgz VEID

or

vzdump --restore /backup/vzdump-VEID.tgz NEW_VEID

VEID = vps id, you can see it using command vzlist
 
:: Links
+ Google
+ OpenVZ
+ HowToForge