Templates Overview

A template in Virtuozzo 6 is a set of application and configuration files installed on a host in such a way as to be usable by any Container. Virtuozzo provides tools for creating templates, installing and removing them on/from hosts, adding them to Containers, and so on.

Using templates, you can:

• Securely share RAM among similar applications running in different Containers to save hundreds of megabytes of memory
• Install applications and patches simultaneously in many Containers
• Use different versions of an application on different Containers (for example, perform an upgrade only in certain Containers)

There are two types of templates in Virtuozzo. These are OS templates and application templates. An OS template is an operating system and the standard set of applications to be found right after the installation. Virtuozzo uses OS templates to create new Containers with a pre-installed operating system. An application template is a set of repackaged software packages optionally accompanied with configuration scripts. Virtuozzo uses application templates to add extra software to existing Containers. For example, you can create a Container on the basis of the redhat OS template and add the MySQL application to it with the help of the mysql template.

In Virtuozzo, you can perform the following operations on templates:

• create new application templates
• list the templates currently installed on the host
• install templates on and remove them from the host
• add templates to Containers
• remove templates from the host and from Containers
• migrate templates from one host to another

All these operations are described in Managing EZ Templates in detail.

Note: The current version of Virtuozzo does not support using templates in virtual machines.