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Summary

Parallels server virtualization products use Parallels Virtual Automation (PVA) for standard backup and restore operations.
Parallels Virtual Automation Agent (PVA Agent) provides backup and restore tools and API for the particular Hardware Node it is installed on.
Parallels Virtual Automation Management Node (PVA MN) provides centralized backup and restore API for all nodes registered in the PVA group.

This article describes the backgrounds of the backup and restore processes, the server roles in the backup and restore processes, and common terms used in PVA.

Server roles

Generally, there are three roles in a backup or restore process:

• Virtualization node - The Hardware Node with the virtual environments to be backed up. It must have Parallels Virtual Automation Agent installed.
• Backup storage node - The Hardware Node used for storing backup data. It must have Parallels Virtual Automation Agent installed.
• Control node - The server initiating the backup process. It must have either Parallels Virtual Automation Agent or Parallels Virtual Automation Management Node installed.

A single server can handle all three roles in the case of a local backup.

Backup scenarios

Scenario	Roles	Example
Local backup of mypvcserver	Virtualization node: mypvcserver Backup storage node: mypvcserver Control node: mypvcserver	vzabackup -F mypvcserver -e CTID
Locally initiated backup to the remote storage	Virtualization node: mypvcserver Backup storage node: remotestorage Control node: mypvcserver	vzabackup  --storage root@remotestorage -F mypvcserver -e CTID
Backup initiated from the storage server remotestorage	Virtualization node: mypvcserver Backup storage node: remotestorage Control node: remotestorage	vzabackup -F mypvcserver -e CTID
Backup of mypvcserver to remotestorage initiated from the third server anotherserver	Virtualization node: mypcvserver Backup storage node: remotestorage Control node: anotherserver	vzabackup --storage root@remotestorage -F mypvcserver -e CTID

Backup tools and interfaces

• Graphical
  1. PVA Control Center - The web interface of PVA MN, allowing you to manage backups for all Hardware Nodes in the PVA group.
  2. Power Panel - The web interface for managing a particular container. A backup initiated from the Power Panel is performed according to the local settings of the Hardware Node the container is hosted on.
  3. Parallels Management Console (obsolete) - A graphical tool shipped with older versions of Parallels Virtuozzo Containers. Allows you to perform backup and restore operations across registered nodes.
• Command-line
  1. vzabackup\vzarestore - CLI interface to PVA Agent Backup API methods.
  2. vzbackup\vzrestore (obsolete)- CLI interface to TAR-based backup; does not require PVA Agent to be running.
     NOTE: On Parallels Virtuozzo Containers for Windows, this is in the form of another wrapper on the vzabackup\vzarestore tool.
• API
  1. Backup interfaces of PVA Management Node XML API.
  2. Backup interfaces of PVA Agent via SOAP and XML API.

Backup back-end

Parallels provides two back-ends for backup files:

1. One that is compatible with Acronis Backup and Restore (default).
2. One that is compatible with TAR.

The backup engine back-end can be switched in the PVA Agent configuration file:

1. Edit the PVA Agent configuration file:
   /vz/pva/agent/etc/vzagent.conf
   or
   /var/opt/pva/agent/etc/vzagent.conf
    
2. Change the backend value, to 0 for Acronis-compatible, or 1 for TAR-based:
   • vzlin_backup_serializer (for pre-PVA 4.6.4 nodes):
     
     <vzlin_backup_serializer> 
     <configuration> 
     <backend>1</backend> 
     <enable_snapshot>1</enable_snapshot> 
     <custom> 
     <queue>0</queue> 
     <heavy_timeout_limit>360000</heavy_timeout_limit>
     </custom> 
     </configuration> 
     </vzlin_backup_serializer> 
   • vzlin_backup_serializer11 (for PVA 4.6.4 and later versions):
     
     <vzlin_backup_serializer11> 
     <configuration> 
     <backend>1</backend> 
     <enable_snapshot>1</enable_snapshot> 
     <custom> 
     <pool>0</pool> 
     <queue>0</queue> 
     <heavy_timeout_limit>360000</heavy_timeout_limit>
     </custom> 
     </configuration> 
     </vzlin_backup_serializer11> 
3. Restart PVA Agent:
   
   pvaagent restart

Also see

8133 How to increase PVA Agent timeouts for backup operations