Storage considerations for Azure Virtual Desktop workloads
This article discusses the storage design area of an Azure Virtual Desktop workload. Azure Virtual Desktop is a cloud-based, end-user compute solution that gives users access to their desktops and applications from anywhere, on any device. This discussion covers storage considerations for virtual machines (VMs), user profiles, and applications.
Important
This article is part of the Azure Well-Architected Framework Azure Virtual Desktop workload series. If you aren't familiar with this series, we recommend that you start with What is an Azure Virtual Desktop workload?.
Region selection
Impact: Performance Efficiency, Cost Optimization
When you deploy Azure Virtual Desktop, region selection is an important consideration. Before you select the Azure region that you want to deploy to, you should check product availability. SKUs for services such as Azure Virtual Machines can vary by region, because not every region contains identical hardware. For the availability of VM SKUs and other services, see Products available by region.
Before you select a specific region, you should also be aware of its regional compliance and data residency requirements.
Another important consideration in region selection is latency. It's generally best to centralize all necessary resources in the same Azure region as your host pool. If you deploy Azure Virtual Desktop in a region that's far from your users, it can increase latency and degrade performance. It can also increase the cost of data transfer between regions.
The Azure Virtual Desktop metadata store contains workspaces, host pools, app groups, and scaling plans. This metadata store isn't always supported in the region that you select for your session hosts. This lack of support can cause the metadata store and session hosts to be separated. For detailed information, see Data locations for Azure Virtual Desktop.
Recommendations
- Check that the VM SKUs and Azure services that you need are available in your selected region.
- Familiarize yourself with the compliance and data residency requirements of any region that you're considering.
- Place your resources in the same Azure region as your host pool to minimize latency and reduce data transfer costs.
- Familiarize yourself with the regions that Azure Virtual Desktop management plane resources are available in.
VM and disk sizing
Impact: Performance Efficiency, Cost Optimization
VM sizing is an important consideration when you deploy Azure Virtual Desktop. Sizing directly affects your cost and end-user experience. Sizing also determines which workloads run smoothly. The overall goal is to right-size your VMs by looking at factors like the resource requirements of your workload and whether you use personal or pooled host pools. It's also preferable to use a larger number of smaller VMs than to use a few large VMs, because it's easier to manage and maintain smaller VMs. For detailed information about VM sizing, see Session host virtual machine sizing guidelines.
Scaling plans provide an efficient way of using small, low-user-density VMs. A scaling plan automatically adjusts the number of VMs based on user demand and schedule. This approach reduces costs by turning off unused VMs. It optimizes resources by matching host pool capacity with user sessions. For more information, see Autoscale scaling plans and example scenarios in Azure Virtual Desktop.
When you select an operating system disk for Azure Virtual Desktop, you can save costs by selecting a standard hard-disk drive (HDD) over a solid-state drive (SSD), but you sacrifice performance. If your production workload requires a service-level agreement (SLA), you should use premium SSD storage.
Another consideration is that Azure VMs have I/O operations per second (IOPS) and throughput performance limits that are based on the VM type and size. The selected SKU of operating system disks and data disks ultimately determines the IOPS that are available to the user. If you use FSLogix profiles, you have extra IOPS requirements, because the profiles are pulled from network shares and written to disk. For detailed information about IOPS and disk performance, see Scalability and performance targets for VM disks.
Recommendations
- Examine the CPU, GPU, memory, and storage usage of the workloads that your users run before you select a VM SKU.
- Use VMs with at least two physical CPU cores for single-session hosts.
- Use VMs with at least four cores for multiple-session hosts.
- Use a larger number of smaller VMs instead of a few large VMs.
- Use scaling plans to adjust your number of VMs based on user demand and schedule.
- Take into account the IOPS and throughput performance limits of your VMs when you select a disk type.
- Use SSDs for high-performance workloads.
- Use premium SSDs for production workloads that require high performance, low latency, and an SLA.
- Use premium SSDs for Windows 10 or Windows 11 Enterprise Multi-Session.
- Use standard or premium SSDs for personal desktops.
User profiles
Impact: Performance Efficiency, Cost Optimization
Azure Virtual Desktop can efficiently handle tasks that are associated with user profiles, such as managing large offline storage table files and persisting modern settings. Overall, FSLogix is the recommended user profile solution for Azure Virtual Desktop. It's designed to roam profiles in remote computing environments. When a user signs in, the FSLogix profile container is dynamically attached to the computing environment via a virtual hard disk (VHD) and a Hyper-V virtual hard disk (VHDX). The user profile is immediately available and appears in the system like a native user profile.
Azure provides several storage solutions for housing FSLogix profile containers for use with Azure Virtual Desktop. In most scenarios, Azure Files is the recommended storage solution for a virtual desktop environment. As long as the capacity, IOPS, and latency meet your needs, Azure Files provides excellent value. Its fully managed file shares minimize maintenance on your part. For detailed information about available storage tiers, see Azure Files tiers.
Another option for an FSLogix storage solution is Azure NetApp Files, which is an Azure-native, enterprise-class, high-performance file storage service. The product tier and capacity that you select for Azure NetApp Files affect its performance. Provisioning more capacity leads to a higher performance budget, which can result in a lower tier requirement. That situation can lead to a more optimal total cost of ownership (TCO). When you select a tier, you need to balance capacity, performance, and cost considerations. For more information about available tiers, see Azure NetApp Files tiers.
The following table provides a quick comparison of storage options for FSLogix:
| Features | Azure Files | Azure NetApp Files |
|---|---|---|
| Use case | General purpose | General purpose to enterprise scale |
| Platform service | Yes, Azure-native solution | Yes, Azure-native solution |
| Regional availability | All regions | Selected regions |
| Redundancy | Locally redundant, zone-redundant, geo-redundant, or geo-zone-redundant | Locally redundant, zone-redundant with cross-zone replication, or geo-redundant with cross-region replication |
| Tiers | Standard (transaction optimized), premium | Standard, premium, ultra |
| Performance | Up to a maximum of 100,000 IOPS per share with 10 GBps per share at about 3-ms latency | Up to a maximum of 460,000 IOPS per volume with 4.5 GBps per volume at about 1-ms latency. For IOPS and performance details, see Performance considerations for Azure NetApp Files and Performance FAQs for Azure NetApp Files. |
| Capacity | 100 TiB per share, up to 5 PiB per general purpose account | 100 TiB per volume, up to 12.5 PiB per NetApp account |
| Required infrastructure | A minimum share size of 1 GiB | A minimum capacity pool of 2 TiB, a minimum volume size of 100 GiB |
| Protocols | Network File System (NFS) 4.1 (preview), Server Message Block (SMB) 3.0, SMB 2.1, REST | NFS 4.1, NFS 3, SMB 3.x, SMB 2.x, dual-protocol |
For detailed information about FSLogix storage solutions, see Storage options for FSLogix profile containers in Azure Virtual Desktop.
Recommendations
- Use FSLogix as your user profile solution for Azure Virtual Desktop.
- Deploy your storage solution for FSLogix profile containers in the same region as your session hosts.
- Check that any storage solution that you're considering supports the protocols that you use.
- Use Azure Files as your storage solution in most scenarios. Consider the following guidelines when you select a tier:
- Use premium file shares for I/O-intensive workloads that require high performance and low latency.
- Use standard file shares for I/O workloads that are less sensitive to performance variability.
- Use standard file shares for a pay-as-you-go billing model.
- Consider using Azure NetApp Files as a storage solution for large-scale Azure Virtual Desktop deployments. Keep the following points in mind:
- Check that Azure NetApp Files is available in your region.
- Consider costs and performance requirements when you select a tier and provision capacity.
- Be aware that the capacity that you provision can affect your choice of tier.
Applications (App Attach)
Impact: Operational Excellence
App Attach is the recommended solution for delivering applications to Azure Virtual Desktop VMs. It offers many benefits for packaging and app management. Examples include increased security, flexibility, and control, and reduced deployment time. For example, you can use App Attach to update apps without affecting user data or settings. It supports desktop and Universal Windows Platform (UWP) apps. App Attach also provides a way for you to use the Windows app installer to install and uninstall apps easily.
App Attach is different from MSIX. App Attach is designed specifically for supported products like Azure Virtual Desktop. In an Azure Virtual Desktop deployment, App Attach delivers apps to session hosts within MSIX containers. These containers separate user data, the operating system, and apps. This separation improves security and increases troubleshooting efficiency. A main benefit of App Attach is that it offers flexibility and control over app delivery. For instance, you can dynamically attach apps from an MSIX package to a user session.
App Attach doesn't have specific dependencies on the type of storage fabric that the file share uses. As a result, the considerations for the App Attach share are the same as the considerations for an FSLogix share. For those considerations, see User profiles, earlier in this article. To learn more about storage requirements, see Storage options for FSLogix profile containers in Azure Virtual Desktop.
Recommendations
Separate the App Attach storage fabric from FSLogix profile containers.
Exclude the following files from antivirus scans to avoid performance bottlenecks:
- <App-Attach-file-share>*.VHD
- <App-Attach-file-share>*.VHDX
- <App-Attach-file-share>.CIM
Exclude the following locations from antivirus scans if you use Azure Files:
- \storageaccount.file.core.windows.net\share*.VHD
- \storageaccount.file.core.windows.net\share*.VHDX
- \storageaccount.file.core.windows.net\share*.CIM
Run a test if you use a multiple-session host to see whether two or more users on the same session host can successfully run the app at the same time.
Include steps in your disaster recovery plans for Azure Virtual Desktop for replicating your App Attach file share in your secondary failover location. Also ensure that the file share path is accessible in the secondary location. Consider using a distributed file system (DFS) namespace to meet this requirement.
Check that the App Attach file share contains the following permissions when you use Azure Files:
Azure object Required role Role function Session hosts (VM computer objects) Storage File Data SMB Share Reader Provides read access to Azure file shares over SMB Admins on file shares Storage File Data SMB Share Elevated Contributor Provides read, write, and delete access and permissions to modify access control lists on files and directories in Azure file shares
Next steps
Now that you've looked at storage considerations, see how to integrate an Azure Virtual Desktop workload with Azure landing zones.
Use the assessment tool to evaluate your design choices.