Backup of a running container with vzdump

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.

There are several ways to provide consistency:

• Stop the CT during backup (very long downtime)
• Use rsync and suspend/resume (minimal downtime)
• Use LVM2 (no downtime)

Vzdump stores the backup on the disk in a single file. This file should go to a tape backup for archiving.

Download

Download vzdump rpm or deb packages from http://download.openvz.org/contrib/utils/vzdump/ or for newest version, check http://www.proxmox.com/cms_proxmox/en/technology/oss-software/openvz/

For rpm based systems:

wget http://www.proxmox.com/cms_proxmox/cms/upload/vzdump/vzdump-1.0-2.noarch.rpm

For Debian based systems:

wget http://www.proxmox.com/cms_proxmox/cms/upload/vzdump/vzdump_1.0-2_all.deb

Installation

For rpm based systems:

rpm -i vzdump-1.0-2.noarch.rpm

For Debian based systems:

dpkg -i vzdump_1.0-2_all.deb

Synopsis

vzdump OPTIONS [--all | <CTID>]
      --compress              compress dump file (gzip)
      --dumpdir DIR           store resulting files in DIR
      --xdelta                create a differential backup using xdelta
      --mailto EMAIL          send notification mail to EMAIL
      --stop                  stop/start container if running
      --suspend               suspend/resume container when running
      --snapshot              use LVM snapshot when running
      --restore FILENAME      restore FILENAME

Examples

Use a running container, for example install this: Proxmox Mail Gateway in container.

Backup

Simply dump CT 777 — no snapshot, just archive the container private area and configuration files to the default dump directory (usually /vz/dump/).

vzdump 777

Use rsync and suspend/resume to create a snapshot (minimal downtime).

vzdump --suspend 777

Backup all containers and send notification mails to root.

vzdump --suspend --all --mailto root

Use LVM2 to create snapshots (no downtime).

vzdump --dumpdir /space/backup --snapshot 777

Note that using LVM2 and vzdump to create snapshots requires 512Mb of free space in your VG as described here.

Restore

Restore the above backup to CT 600:

vzdump --restore /space/backup/vzdump-777.tar 600

Bugs

vzdump will fail under Debian Etch in version 1.0-2 if it is invoked with parameter "--snapshot" and if the logical volume name contains a hyphen. One possible workaround is to rename the logical volume in question thus it doesn't contain any hyphen. A bug report was sent to proxmox on 02 June 2008. Other distributions or versions may be affected, too.