Introduction

Purpose

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

Feature Specifications

• 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.
• In case of pooled desktops if a VM is already restarted and got pointed to the new updated base image, then when the restart of other VMs it should check for the new updated base image (already downloaded previuosly) and point to that.

Use cases

The usual way to point out to the new base image is to destroy the machine and recreate with the new disk. But this causes problem due to the change of ipaddress.This feature persists the network identity of the existing VMs even after base image updation.

Architecture and Design description

• Some changes to the RestoreVM api can achieve this as this api persists the netowrk identity.
• Adding the same what we do for the upgrade of system vm template.

web services APIs

restoreVirtualMachine API needs to be modified to achieve this feature.

UI flow

• need to be updated

Appendix

Appendix A:

Appendix B: