We regularly take new snapshots of a VMs vhds before testing major development changes, adding Windows updates, testing new application settings etc., to allow us to easily revert to the previous state of the VM if desired. In Azure, snapshots are taken of the virtual disks (vhd), not the VM instance itself. Snapshots are full, read-only copies of the vhds.

An Azure snapshot of a data or operating system (os) vhd can be used:

  • For custom backup/restore of a VMs vhds
  • For troubleshooting disk problems.
  • To create a copy of production servers for use in development, or the opposite, copy a dev environment into production mode.
  • To quickly duplicate a fresh VM instance. For example, we use specific single-tier and double-tier web server/sql server environments that need to be reproduced for various testing scenarios. A new ‘exact copy’ environment, with all accounts and applications in place, can be ready for access within 5 minutes if necessary, using stored Azure Snapshots of the OS and data disks. These are considered ‘specialized’ disks…
  • To create a ‘repository’ of prepared specialized OS and data disks for use in creating multiple VM copies.
  • To create a dr backup repository of snapshots in a different region or subscription (or both), in case of accidental deletion of key OS or data disks.
  • Backing up a VM before making a major change – although it is not possible to revert the VM to the previous state, the VM can be deleted and using the saved snapshots > create new managed OS and data disks > create a new VM using the previous VMs Nic, etc.
Create a snapshot from the Azure Portal:

1. Login to Azure Portal
2. Create a resource > Search ‘Snapshot’ > Create

3. Name the snapshot, choose Subscription, Resource Group, Location, choose the Source Disk from the subscription’s disks shown in the dropdown, set the Account type > Create:

4. The new snapshot ‘2016DemoSnapshot‘ is now showing in the list of Snapshots available on the Azure account: