When it comes to working with virtual machine (VM) templates, the guest customizations will save you a lot of time. It may seem like using a VM and perpetually cloning it is the right thing to do within vSphere, but it's not — it's likely that settings will be missed, configuration will drift, and time will be wasted. The best steps to take are to: use guest customization, install each VM individually, or use automated installs that start automatically on boot.For vSphere environments, we have the guest customization wizards within vSphere that make quick work of this task. When we deploy a VM from a template, there are a number of important options (such as what the VM name will be and where it will reside within the vSphere infrastructure), though none of the options configure the guest VM. During a template deployment, we have the option to configure a customization wizard (Figure A). Figure A
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The middle option allows a customization to be created for use with other VMs deployed. The best part of vSphere's customization wizard is that Windows Server 2008 and Windows 7 customization is built-in; for Windows Server 2003 and Windows XP systems, there is a required addition of the Sysprep files to the vSphere Server.The customization wizard is straight-forward and intuitive. Some of the options in the wizard (Figure B) include:
- Registered Name And Organization: This is what will show up in the Properties of My Computer.
- NetBIOS Name For Virtual Machine: The best option is to use the VM name specified in the earlier part of the wizard to ensure consistency.
- Specify A Windows Product Key: If a Multiple Activation Key (MAK) is used, it can be specified in the wizard and per seat or per server options selected.
- An Administrator Password Specified: This is for the local built-in administrator account.
- A Time Zone: Finally, a way to get the local time zone configured correctly!
- A Run Once Command: Any post-installation scripts to run on the VM.
- Network Settings: This includes custom IP address configuration (DNS, DHCP, or static).
- Active Directory: The option to join a domain automatically is available.
- Generate new SID: This is important, so that each VM has a unique identifier.
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I encourage you to configure the customization options for vSphere because it can save you time and prevent configuration drift from templates.
How many guest customizations do you maintain? Let us know in the discussion.
Rick Vanover is a software strategy specialist for Veeam Software, based in Columbus, Ohio. Rick has years of IT experience and focuses on virtualization, Windows-based server administration, and system hardware.