Let’s Go Deep! (Technically):   Leveraging Virtual Machine Templates in Virtual Center

A number of VI3 deployments aren’t configured to use virtual machine (VM) templates. This easily configured feature quickly brings the latest version of VMware ESX Server and the VI3 suite big bang for the buck. Unlike Windows workstation or server imaging using SYSPREP, VM templates make it easy to capture and convert a Windows installation into a template for quickly deploying multiple Windows virtual machines in moments.

One big advantage of VM templates is that the source operating system (OS) remains unaffected. SYSPREP customization applies only to guests deployed using the template, leaving the source VM untouched.   This “step-by-step” assumes that Virtual Center is deployed, that you know your way around the Virtual Infrastructure Client (VIC), and that you’ve installed a Windows VM on ESX. You also need the latest version of the deployment tools (DEPLOY.CAB) for the version of Windows you’re using as well as a general understanding of SYSPREP.

Having built, patched, and configured the Windows VM, “power down” the guest. In the VIC, right click the VM and choose “Convert to Template” (or “Clone to Template”). If the new virtual machine template disappears, switch the Inventory view to “Virtual Machines and Templates” and make sure that “Show Templates” is checked. Templates are clearly discernable from VMs in the VIC.

Before deploying from the template, Virtual Center (VC) must be configured to use SYSPREP for guest customization. On the VC server, the path “C:\Documents and Settings\All Users\Application Data\VMware\VMware VirtualCenter\sysprep” has subfolders for Windows 2000, and for 32- and 64-bit versions of Server 2003 and XP. Each OS requires unique and specific versions of SYSPREP, and the respective folders should be populated using the most recent version for each.

To deploy, simply Right Click the template and choose “Deploy Virtual Machine from this Template”.    The “Deploy Template Wizard” uses a clear set of prompts to assign a name, host server, and datastore for the new VM. If SYSPREP files aren’t correctly configured the only option on the Guest Customization screen will be “Do not customize” with a warning that states “Windows Customization resources were not found on the server.”

SYSPREP customization specifications can be saved for later use. Modify existing customization specifications using the Edit, Customization Specifications menu in the “Virtual Machines and Templates” view. It really is that simple. If you need help getting up to speed, C/D/H can help you learn to automate VM deployment using Virtual Machine Templates.