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Restoring a VM from a Snapshot


Course Introduction
Imaging Basics
1m 44s
4m 53s
Session Hosts and Images
Course Conclusion
Start course

This course covers imaging in Azure to show you how you can build Azure Virtual Desktop session hosts as well as prepare for the AVD Specialty exam. This is going to cover a lot of information on the Windows OS, imaging tools, and how we work with images in Azure. Then we'll look at how to manage, maintain, and update those images. Finally, we'll cover how you can automate the whole process so you can scale as well as generate a new image each month or when a zero-day patch comes out, so you can stay secure.

Learning Objectives

  • Create a custom image
  • Deploy a session host with a custom image
  • Modify a session host image
  • Install language packs
  • Plan for image update and management
  • Create and use Azure Compute Gallery image
  • Automate custom images with Azure Image Builder

Intended Audience

  • Azure administrators with subject matter expertise in planning, delivering, and managing virtual desktop experiences and remote apps, for any device, on Azure
  • Anyone looking to learn more about Azure Virtual Desktop


  • Windows operating system
  • Imaging a Windows OS
  • Azure Virtual Machines
  • VM snapshots
  • Azure Compute Gallery 
  • Azure Image Builder

Now that you have a snapshot created, let's go through how you would restore your VM from the snapshot, in case you had a problem. Now, a virtual machine and disc are two separate resources that are attached together to make Windows work. When you created a snapshot, that is an additional resource that contains a copy of the VM disc. So our process here will be to create a disc from that snapshot, detach the current disc from the virtual machine and then attach our restored disc in its place. This is a great process because it allows you to jump easily between versions of that Windows VM, for troubleshooting, testing of several variations. And it only takes as long as a reboot to get back up and running.

To do this from inside your snapshot, at the top click to create a disc, the subscription and resource group will be selected for you and you need to give your new VM disc a name, as well as select any availability zone, if applicable. At the bottom, you can set the size for your new disc. Just note that you can't make it smaller than the original disc was, but it can be larger, depending on the size, this could also increase performance. For those encryption and networking tabs, you'll wanna set these as you did originally when you took the snapshot. But again, if you don't require extra encryption or network layer security on your VM disc, I would just take the defaults.

Then click over to the advanced tab. The options on this screen are generally not applicable for an operating system disc, but I want you to know what they are. A shared disc is usually used in a clustering solution, where you'll have multiple virtual machines that need to be able to write to the same disc at the same time. On-demand bursting is available on discs that are 512 gigabytes or larger. And that's where you can gain extra disc performance or greater throughput in short bursts, beyond what is normally allocated to a disc of that size.

Since operating system discs cannot be shared, and OS discs rarely get as large as 512 gigabytes, we won't be using these options in this course. So just click next, add your tags. And these are the metadata, and that should be associated with your standard policy for tagging VM discs. And when you're ready, create your disc. Now that we have a restored disc from our snapshot go back to your virtual machine and on the left, select disc. Near the top, click on that button to swap an OS disc click the dropdown, and choose your disc.

In the top portion, it shows the available discs in the same resource group as your VM and at the bottom, you'll see every available disc in your subscription in the same region as your VM. Click on the restored disc. Now you'd want to confirm this process by typing the name of the VM in the box and then click okay at the bottom. The swap will only take a moment and it'll be brought back to the disc screen and you should see the restored disc under the VM disc name.

About the Author
Dean Cefola
Principal Azure Engineer

Dean Cefola is a Principal Azure Engineer at Microsoft and has worked in the IT industry for over 20 years. Dean has been supporting Azure Virtual Desktop from the beginning and is the Microsoft FastTrack Global Leader for AVD.