How to Properly Allocate Resources in Azure Virtual Desktop

Articles
Neil McLoughlin

20 November, 2023
5 min read

Azure Virtual Desktop consists of multiple Azure resources. They must be placed in the appropriate locations for maximum availability and performance to get the best end-user experience. This blog post will discuss the resources relevant to Azure Virtual Desktop (AVD) and some related considerations for effective and efficient IT management.

Resources in Azure Virtual Desktop (AVD)

Entra ID Tenant

Before deploying anything, the first Azure resource you need is an Entra ID tenant. An Entra ID tenant is a global resource. The tenant you choose for AVD must be Entra ID, formerly known as the Azure Active Directory (Azure AD) tenant, which contains the users for whom you want to assign AVD resources. Most organisations will already have an Entra ID tenant used for Microsoft 365 services.

Azure Subscriptions

The next resource you need to choose is the Azure subscription. This is a critical decision: one that IT admins must carefully consider when planning and deploying AVD. The number of hosts deployed typically determines the number of Azure subscriptions used in deployment. You also need to determine whether the subscriptions should be split up by business unit or department for easier cost control or management. To better understand the reasons behind a decision, please view this article by Microsoft – https://learn.microsoft.com/en-us/azure/architecture/example-scenario/wvd/windows-virtual-desktop

Nerdio can manage multiple subscriptions in one single plane of glass for easier and simplified management. Learn more at www.getnerdio.com/nerdio-manager-for-enterprise

Azure Resource Groups

Now that you’ve configured tenants and subscriptions, it’s time to create some resources! Before you can make any resources, you’ll need some resource groups. Think of a resource group as a folder.

You can create resource groups for different departments, countries, business units, host pool types, etc. These depend on how your Azure Landing Zone designs stipulate how those resource groups are split up. Typically, in an AVD environment, you would create a resource group for each host pool. We usually see VMs, NICs (network interface cards) and storage accounts located in the resource groups.

Virtual Machine (VM) SKUs

A virtual machine (VM) consists of three things: compute, storage and networking. Around 70% of AVD costs will come from the Azure compute.

Within Azure, there are multiple VMs SKUs available, tailored for different use cases. Some are geared towards general use, some are geared towards processing power, some are geared towards higher memory usage, some use GPUs etc, etc. The primary VM types we come across at Nerdio are:

D-Series – These VM types are geared towards general use and have a good balance of CPU and memory. For example, a D8S_V5 has 8 vCPUs and 16GB of memory, so a 1:2 ratio.

F-Series – The F-Series VM types are geared towards users with higher CPU requirements. For example, a F8S_V2 has 8 vCPUS and 16GB of memory and a 1:2 ratio but with a much faster CPU.

E-Series – The E-Series VM types are geared towards users with higher memory requirements. For example, a E8a_v5 has 8 vCPUs and 64GB RAM, so a 1:4 ratio.

N-Series – We also have N-Series VMs, which contain GPUs.

Nerdio has advanced auto-scaling capabilities to turn off these VMs when not in use. This can reduce up to 85% of your Azure compute costs. You can read this blog post by my colleague Tony Cai to better understand VM SKUs and how to “decode” them.

Managed Disks

After you pick your VM SKU, the next choice to make is what managed disk SKU to use. Within Azure, there are three different types of disks:

Standard HDD — Use for non-production workloads with around 500 IOPS and 60 MB/sec throughput for a 128GB Disk.

Standard SSD — Use for single-session desktops and multi-session hosts with fewer users. Maximum IOPS is 500 IOPS, and around 60 MB/sec for a 128GB Disk.

Premium SSD – Use for multi-session or single-session hosts for those with higher disk requirements. Maximum IOPS is 500 IOPS (3500 Burst), and 100 MB/sec throughput for a 128GB Disk.

Using Nerdio’s auto-scaling capabilities, we switch the Disk SKU from a Premium SSD to a Standard HDD to reduce your overall Azure storage costs.

FSLogix Storage

Most multi-session environments use a tool called FSLogix, which redirects the user’s profile to a VHD or VHDX file located on a file share. You should place the file share containing these profile disks as close to the host pools as possible, ideally in the same region. Otherwise, the users will experience prolonged logon times and slow performance. There are several different storage options available via Azure Files:

Azure Files Standard – These are HDD-backed and only recommended for smaller environments. Microsoft architectural guidance states that you should put no more than 200 users on the standard.

Azure Files Premium – Azure Files Premium is the most common storage type for FSLogix profiles. Azure Files Premium uses SSD disks and provides much higher IOPS and throughput for profile storage.

Depending on the host pool size, it is best practice to have an FSLogix profile share per host pool to achieve maximum performance and flexibility. However, if users share host pools, it may make sense to share the profile claims to save the users from having multiple profiles.

Nerdio’s auto-scaling capabilities will auto-grow and auto-shrink the FSLogix storage shares to ensure you are paying the least for those resources.

Networking

The next type of Azure resource to deploy is the networking resources needed to connect to a session host. For an AVD deployment, you typically create a VNET, a subnet within that, and each subnet will contain multiple NICs belonging to the session hosts.

The networking defines the location of the VM you are deploying. So it is a critical decision where you place your session hosts. Ideally, you want to put those VMs as close to the users as possible to give the best user experience. Still, you must also remember the location of the backend resources that those desktops will connect to. You can use this free Microsoft tool to find your nearest Azure location – https://azure.microsoft.com/en-gb/products/virtual-desktop/assessment/#estimation-tool

Log Analytics

The final Azure resource to discuss is the Log Analytics workspace. This gathers session data and can also be used to collect performance metrics for your session hosts.

Typically, there will be one central log analytics workspace in most environments to collect data for multiple host pools and AVD workspaces. It is advised to have one per region, ideally.

Log Analytics workspaces can get expensive very quickly if not managed properly. We advise you to set the retention ratio to only the duration you need to report on the data and collect the data you need. You can customize the Log Analytics counters to meet your specific needs.

Nerdio can manage the Log Analytics workspace for you, allowing you to easily see the costs, manage the retention duration, and manage which counters are being collected.

Conclusion

As discussed, an Azure Virtual Desktop (AVD) solution comprises many different resources, which can vary in SKU types, location, and many other factors. When planning an AVD environment, resources must be all thought about and planned. If you get it wrong, you can have a costly solution with very poor performance. But, if done right, organizations can leverage a very cost-effective solution with excellent performance.