Introduction
VZDump is a utility to make consistent snapshots of running OpenVZ containers. It basically creates a tar archive of the container's private area, which also includes the CT configuration files.
Download
VZDump can be obtained from Proxmox website.
Usage
vzdump can create backups in several ways. To get all available options, use:
# vzdump
usage: /usr/sbin/vzdump OPTIONS [--all | VPSID]
--exclude VPSID exclude VPSID (assumes --all)
--exclude-path REGEX exclude certain files/directories
--stdexcludes exclude temorary files and logs
--compress compress dump file (gzip)
--dumpdir DIR store resulting files in DIR
--tmpdir DIR store temporary files in DIR
--mailto EMAIL send notification mail to EMAIL.
--quiet be quiet.
--stop stop/start VPS if running
--suspend suspend/resume VPS when running
--snapshot use LVM snapshot when running
--size MB LVM snapshot size
--node CID only run on pve cluster node CID
--lockwait MINUTES maximal time to wait for the global lock
--stopwait MINUTES maximal time to wait until a VM is stopped
--bwlimit KBPS limit I/O bandwidth; KBytes per second
--restore FILENAME restore FILENAME
Special notes on LVM based deployments
vzdump is able to backup the running containers with 0 downtime once using lvm snapshots capabilities. Use: --suspend option to enable the use of the lvm snapshots.
Warrning: to be able to use --suspend option, you should have the --dumpdir argument pointing to a location different from the current LVM VG. Also, you should leave at least 512Mb (1G will surely be fine) of free space inside the containers LVM VG. Otherwise you won't be able to get --suspend for backups. Here is an example of an OpenVZ partitioning under Ubuntu 8.04.3: