With templates, system administrators can save a baseline configuration for any Windows or Linux guest operating system. Thus a system administrator can create a template of baseline server configurations to expedite the deployment of servers. Templates can be created for file servers, application servers or Web servers or even "small" or "large" server configurations. Antivirus, systems management agents and other tools can be installed and saved within templates, enabling a fully configured server guest OS upon deployment. You can use simple processes in VirtualCenter -- such as Clone to Template, which creates a new virtual machine by copying the virtual disks and creating new configuration files, or Convert to Template, which transforms the active guest OS into a template – to create templates.
And indeed, whether you're deploying a new Windows or Linux system, creating a new guest OS from a template is relatively straightforward. To deploy a Windows server, VirtualCenter leverages the Microsoft Sysprep utility, enabling the creation of an answer file and integration into the Customization Specification Manager wizard within VirtualCenter. When a new Linux guest OS is requested, Linux leverages the Customization Specification Manager in VirtualCenter.
You manage templates through VirtualCenter. Templates can be powered on to tweak configurations, install updates or new software and, with newer Virtual Infrastructure updates, to deploy updates to guest OSes built on the template.
- Ensure that VMware Tools is installed in every template to ensure that the guest OS performs at an optimal rate by using specified VMware drivers for memory, I/O access, and other components.
- Install Allbase software (i.e., agents, antivirus) into each template. This minimizes repetitive post-deployment procedures that may need to be taken on any guest OS by ensuring all required software is pre-deployed in the template. Any software updates can be added to the template. For antivirus and regular Windows updates, regularly power on each template and download and/or install any available updates.
- Defragment the guest OS disk before creating and saving the template; this ensures that the file system is laid out efficiently across the disk for every deployment.
- Ensure configuration management of templates. Document any changes and updates to your configured templates. VMware provides a notes section for each template that can be used to document modifications or changes to the template.
About the author: Craig A. Newell is a senior consultant at Focus Consulting (www.focusonsystems.com) in Boulder, Colo. He helps end users evaluate technology needs concerning virtualization, server consolidation and blade systems. Newell is a certified project management professional, a certified wireless network administrator, and a certified business continuity planner and served as a technical editor for the book Blade Servers and Virtualization: Transforming Enterprise Computing While Cutting Costs. This was first published in November 2007
This was first published in November 2007