A template in Parallels Virtuozzo Containers is a set of application files and registry settings installed on the Host operating system in such a way as to be usable by any Container by mounting over Virtuozzo File System.
Using templates, only a single instance of a software package is required and managed on a physical machine, regardless of the number of containers using the software. Parallels Virtuozzo Containers templates are very small and can be deployed in seconds.
Advantages of this approach include the following:
Templates reduce the duplication of software used multiple times on a virtualized server, making it possible to manage a single instance of software on a server.
Templates can be deployed and updated online without any downtime or restarting the physical server.
Because multiple containers can share real memory, Parallels Virtuozzo Containers enables 3-10 times greater density for typical workloads, as compared with other virtualization technologies.
Patches and updates can be applied to a single template, and then the changes can be automatically propagated across all similar templates that reflect the update, dramatically cutting maintenance time.
The Templates Catalog for Parallels Virtuozzo Containers is a library of more than 350 software downloads that can be used to easily create and manage operating systems and applications running in virtual environments. The catalog includes a number of Linux distributions, such as CentOS, Debian, Red Hat Enterprise Linux, SUSE Linux Enterprise Server and Ubuntu, as well as applications like MySQL, Spam Assassin, Wordpress and more.