Introduction

Branch

master, 4.1.0

Purpose

This is functional specification for the feature "Base image update facility", the purpose is that we need to be able to update existing VM with new base image.

...

• When base image update has been performed (e.g. Windows patches applied to the golden master image) then on vm restart there is a need of pointing the VM at the new golden master.
• We need to be able to update existing VMs with a new base image to support the pooled desktop.
• Since the template should be immutable, if the new version of template is created, then it is another template. So vm should boot up using the new template.
• Adding to this, we should have a method to reset a vm on reboot, i.e, discard the root disk and create a new one whenever the vm is rebooted. 
• Currently we support base image updation and reset a vm on reboot for the VMs deployed using templates.

Use cases

The usual way to point out to the new base image is to destroy the machine and recreate with the new disk.

...