Managing VMs

[jessek]

Let's say I want to create a number of VMs for different potential user groups. Each group needs some unique configuration, however each VM will share the same basic configuration. For example:

- Windows 7

- Latest Windows updates

- IE 9

- A few global software tools (that all users in the organization need)

Ideally, I would have a single "base VM" with all the above components, and then I would create additional VMs with specific additions (software for specific user groups, departments, etc).

So if I want to create 3 unique images for Departments X, Y and Z, I would already have a base VM to start from in each case, rather than have to do 3 complete VM installations from scratch.

How should I handle this? Should I just create the base VM and then copy/paste it on my PC, rename it and tweak it further for each VM? Are differencing images related to this at all?

Just trying to find out what the best practices are here rather than waste time (and hard drive space) on lots of duplicate VMs.

Thanks

Jesse

[Erik]

Hi Jesse,

Depending on your virtualization software you can use a number of different options.

• Cloned VMs: Install Windows 7 and the applications/settings that are common across all configurations to one virtual machine. Once you have the base line create clones of this VM so you do not have to reinstall Windows and the common applications for every configuration. You can then make your changes and capture the images. In this scenario you will use more disk space as you have one full blown install for each configuration but it is much easier to manage and capture.
  
• Snapshots: Most virtualization products allow for the capture of snapshots, or a place in time restore point. By utilizing these you could create the base installation, snapshot it and then continue to build your first configuration. Once complete you can revert to the base snapshot and continue to build your second configuration. Once they are all complete you would apply the snapshot for the configuration you want to capture then run the Capture Wizard. The caveat with this is that capture will need to be done by booting the virtual machine to the SmartDeploy boot environment so the correct configuration is captured.
  
• Differencing Disks or Linked Clones: Differencing disks and linked clones basically work by referencing a base disk that would be the base line installation of Windows 7. They are a bit easier to manage than multiple snapshots because they are logically separated. In this scenario you would still need to capture the image form the SmartDeploy boot environment.
  

As for differencing images, they are intended to keep an image up to date over time by creating a smaller update file rather than recapturing an entire WIM. You could create differencing WIMs off of one of your base installs but I would suggest creating a single combined WIM instead. When you create the combined WIM (done by specifying an existing WIM in the Capture Wizard when capturing a new configuration) you will see multiple entries in the image name drop down when selecting your image from the Deploy Wizard. You could then have all the configurations in one single WIM and simply change the drop down to deploy the referenced configuration.

Thanks,

Erik