A VSDM “Template” is a Virtual Machine Hard Disk image that is used as a master image. Like the image that generates a CD that will be applied to a blank media, a virtual template works in an analogous way.
Once the user creates an image based on the template, they will have a “clone” (yet not expensive) replica of the original template that he can change without affecting the original image.
The system works in steps:
- VSDM Administrator publishes a template to the user (either using the Wizard or by editing vsdm_config.xml file directly)
- User creates new Virtual Machines based on those templates
- User changes the machine (remember, it does not affect the template)
- VSDM Administrator can make the new machine into another template for later usage.
For example, the following steps are common scenarios for use with the tool:
- VSDM Administrator makes available an image of Windows Server 2003 CD
- User creates an “Umanaged machine” (not attached to any template), and install Server 2003 on the image
- VSDM Administrator makes this “clean OS” into a template => “Server 2003 RTM”
- User creates another machine based on the new “Server 2003 RTM” template
- User installs Service Pack 1 on that machine
- VSDM Administrator makes this changed machine into another template => “Server 2003 SP1”
From now on, the system contains 2 templates, and any user can quickly get a “Server 2003 RTM” or “Server 2003 SP1” machine to work right away. But notice that the administrator interaction is very quickly and limited, freeing this usually expensive resource to take care of more critical tasks.