Azure Stack HCI solution overview

Applies to: Azure Stack HCI, version 20H2

Azure Stack HCI is a hyperconverged infrastructure (HCI) cluster solution that hosts virtualized Windows and Linux workloads and their storage in a hybrid, on-premises environment. Azure hybrid services enhance the cluster with capabilities such as cloud-based monitoring, Site Recovery, and virtual machine (VM) backups, as well as a central view of all of your Azure Stack HCI deployments in the Azure portal. You can manage the cluster with your existing tools including Windows Admin Center and PowerShell.

Azure Stack HCI, version 20H2 is now available for download. It's intended for on-premises clusters running virtualized workloads, with hybrid-cloud connections built-in. As such, Azure Stack HCI is delivered as an Azure service and billed on an Azure subscription. Azure Stack HCI also now includes the ability to host the Azure Kubernetes Service; for details, see Azure Kubernetes Service on Azure Stack HCI.

Take a few minutes to watch the video on the high-level features of Azure Stack HCI:

From a hardware standpoint, each Azure Stack HCI cluster consists of between 2 and 16 physical, validated servers running a specialized operating system purposely defined for hyperconverged infrastructure. The clustered servers share common configuration and resources by leveraging the Windows Server Failover Clustering feature.

At its core, Azure Stack HCI is a solution that combines the following:

  • Azure services
  • Windows Admin Center
  • Hyper-V-based compute resources
  • Storage Spaces Direct-based virtualized storage
  • Software Defined Networking (SDN)-based virtualized networking using Network Controller (optional)
  • Azure Stack HCI operating system
  • Validated hardware from an OEM partner

The Azure Stack HCI OS runs on top of validated hardware, is managed by Windows Admin Center, and connects to Azure

Azure Stack HCI, version 20H2 provides new functionality not present in Windows Server, such as the ability to use Windows Admin Center to create a hyperconverged cluster that uses Storage Spaces Direct for superior storage price-performance. This includes the option to stretch the cluster across sites and use automatic failover. See What's new in Azure Stack HCI for details.

Azure Stack HCI use cases

There are many use cases for Azure Stack HCI, although it isn't intended for non-virtualized workloads. Customers often choose Azure Stack HCI in the following scenarios.

Use case Description
Branch office and edge For branch office and edge workloads, you can minimize infrastructure costs by deploying two-node clusters with inexpensive witness options, such as Cloud Witness or a USB drive–based file share witness. Another factor that contributes to the lower cost of two-node clusters is support for switchless networking, which relies on crossover cable between cluster nodes instead of more expensive high-speed switches. Customers can also centrally view remote Azure Stack HCI deployments in the Azure portal. To learn more about this workload, see Deploy branch office and edge on Azure Stack HCI.
Virtual desktop infrastructure (VDI) Azure Stack HCI clusters are well suited for large-scale VDI deployments with RDS or equivalent third-party offerings as the virtual desktop broker. Azure Stack HCI provides additional benefits by including centralized storage and enhanced security, which simplifies protecting user data and minimizes the risk of accidental or intentional data leaks. To learn more about this workload, see Deploy virtual desktop infrastructure (VDI) on Azure Stack HCI.
Highly performant SQL Server Azure Stack HCI provides an additional layer of resiliency to highly available, mission-critical Always On availability groups-based deployments of SQL Server. This approach also offers extra benefits associated with the single-vendor approach, including simplified support and performance optimizations built into the underlying platform. To learn more about this workload, see Deploy SQL Server on Azure Stack HCI.
Trusted enterprise virtualization Azure Stack HCI satisfies the trusted enterprise virtualization requirements through its built-in support for Virtualization-based Security (VBS). VBS relies on Hyper-V to implement the mechanism referred to as virtual secure mode, which forms a dedicated, isolated memory region within its guest VMs. By using programming techniques, it's possible to perform designated, security-sensitive operations in this dedicated memory region while blocking access to it from the host OS. This considerably limits potential vulnerability to kernel-based exploits. To learn more about this workload, see Deploy Trusted Enterprise Virtualization on Azure Stack HCI.
Azure Kubernetes Service (AKS) You can leverage Azure Stack HCI to host container-based deployments, which increases workload density and resource usage efficiency. Azure Stack HCI also further enhances the agility and resiliency inherent to Azure Kubernetes deployments. Azure Stack HCI manages automatic failover of VMs serving as Kubernetes cluster nodes in case of a localized failure of the underlying physical components. This supplements the high availability built into Kubernetes, which automatically restarts failed containers on either the same or another VM. To learn more about this workload, see What is Azure Kubernetes Service on Azure Stack HCI?.
Scale-out storage Storage Spaces Direct is a core technology of Azure Stack HCI that uses industry-standard servers with locally attached drives to offer high availability, performance, and scalability. Using Storage Spaces Direct results in significant cost reductions compared with competing offers based on storage area network (SAN) or network-attached storage (NAS) technologies. These benefits result from an innovative design and a wide range of enhancements, such as persistent read/write cache drives, mirror-accelerated parity, nested resiliency, and deduplication.
Disaster recovery for virtualized workloads An Azure Stack HCI stretched cluster provides automatic failover of virtualized workloads to a secondary site following a primary site failure. Synchronous replication ensures crash consistency of VM disks.
Data center consolidation and modernization Refreshing and consolidating aging virtualization hosts with Azure Stack HCI can improve scalability and make your environment easier to manage and secure. It's also an opportunity to retire legacy SAN storage to reduce footprint and total cost of ownership. Operations and systems administration are simplified with unified tools and interfaces and a single point of support.

Azure integration benefits

Azure Stack HCI is uniquely positioned for hybrid infrastructure, allowing you to take advantage of cloud and on-premises resources working together and natively monitor, secure, and back up to the cloud.

After you register your Azure Stack HCI cluster with Azure, you can use the Azure portal initially for:

  • Monitoring: View all of your Azure Stack HCI clusters in a single, global view where you can group them by resource group and tag them.
  • Billing: Pay for Azure Stack HCI through your Azure subscription.

We're working hard on creating additional capabilities, so stay tuned for more.

You can also subscribe to additional Azure hybrid services:

  • Azure Site Recovery for high availability and disaster recovery as a service (DRaaS).
  • Azure Monitor, a centralized hub to track what's happening across your apps, network, and infrastructure – with advanced analytics powered by AI.
  • Cloud Witness, to use Azure as the lightweight tie-breaker for cluster quorum.
  • Azure Backup for offsite data protection and to protect against ransomware.
  • Azure Update Management for update assessment and update deployments for Windows VMs running in Azure and on-premises.
  • Azure Network Adapter to connect resources on-premises with your VMs in Azure via a point-to-site VPN.
  • Azure File Sync to sync your file server with the cloud.

For more information, see Connecting Windows Server to Azure hybrid services.

Why Azure Stack HCI?

Azure Stack HCI is a world-class, integrated virtualization stack built on proven technologies that have already been deployed at scale, including Hyper-V, Storage Spaces Direct, and Azure-inspired software-defined networking (SDN). There are many reasons customers choose Azure Stack HCI, including:

  • It's familiar for Hyper-V and server admins, allowing them to leverage existing virtualization and storage concepts and skills.
  • It works with existing data center processes and tools such as Microsoft System Center, Active Directory, Group Policy, and PowerShell scripting.
  • It works with popular third-party backup, security, and monitoring tools.
  • Flexible hardware choices allow customers to choose the vendor with the best service and support in their geography.
  • Joint support between Microsoft and the hardware vendor improves the customer experience.
  • Seamless, full-stack updates make it easy to stay current.
  • A flexible and broad ecosystem gives IT professionals the flexibility they need to build a solution that best meets their needs.

What you need for Azure Stack HCI

To get started, here's what you need:

  • A cluster of two or more servers from the Azure Stack HCI Catalog, purchased from your preferred Microsoft hardware partner
  • An Azure subscription
  • An internet connection for each server in the cluster that can connect via HTTPS outbound traffic to well-known Azure endpoints at least every 30 days
  • For clusters stretched across sites, you need at least one 1 Gb connection between sites (a 25 Gb RDMA connection is preferred), with an average latency of 5 ms round trip if you want to do synchronous replication where writes occur simultaneously in both sites
  • If you plan to use Software Defined Networking (SDN), you'll need a virtual hard disk (VHD) for the Azure Stack HCI operating system to create Network Controller VMs (see Plan to deploy Network Controller)

For more information, see System requirements. For Azure Kubernetes Service on Azure Stack HCI requirements, see AKS requirements on Azure Stack HCI.


Aspect Details
Release state: General Availability (GA)
Pricing: Billed to Azure subscription
Required roles and permissions: Azure Active Directory Administrator or delegated permissions

Hardware partners

You can purchase validated Azure Stack HCI solutions from your preferred Microsoft partner to get up and running without lengthy design and build time. Microsoft partners also offer a single point of contact for implementation and support services. You can either purchase validated nodes or an integrated system, which includes the Azure Stack HCI operating system pre-installed as well as partner extensions for driver and firmware updates.

Visit the Azure Stack HCI solutions page or browse the Azure Stack HCI Catalog to view 70+ Azure Stack HCI solutions currently available from Microsoft partners such as ASUS, Axellio, Blue Chip, DataON, Dell EMC, Fujitsu, HPE, Hitachi, Huawei, Lenovo, NEC, primeLine Solutions, QCT, SecureGUARD, and Supermicro.

Software partners

There is a variety of Microsoft partners working on software that extends the capabilities of Azure Stack HCI while allowing IT admins to use familiar tools. To learn more, see Utility applications for Azure Stack HCI.

Licensing, billing, and pricing

Azure Stack HCI billing is based on a monthly subscription fee per physical processor core, not a perpetual license. When customers connect to Azure, the number of cores used is automatically uploaded and assessed for billing purposes. Cost doesn’t vary with consumption beyond the physical processor cores, meaning that more VMs don’t cost more, and customers who are able to run denser virtual environments are rewarded.

Customers can either purchase validated servers from a hardware partner with the Azure Stack HCI operating system pre-installed, or they can buy validated bare metal servers from an OEM and then subscribe to the Azure Stack HCI service and download the Azure Stack HCI operating system.

The Azure Stack family

Azure Stack HCI is part of the Azure and Azure Stack family, using the same software-defined compute, storage, and networking software as Azure Stack Hub. The following provides a quick summary of the different solutions. For more information, see Comparing the Azure Stack ecosystem.

  • Azure - Use public cloud services for on-demand, self-service computing resources to migrate and modernize existing apps and to build new cloud-native apps.
  • Azure Stack Edge - Accelerate machine learning workloads and run containerized apps or virtualized workloads on-premises, on a cloud-managed appliance.
  • Azure Stack HCI - Run virtualized apps on-premises, replace and consolidate aging server infrastructure, and connect to Azure for cloud services.
  • Azure Stack Hub - Run cloud apps on-premises, when disconnected, or to meet regulatory requirements, using consistent Azure services.

Azure Stack family solution diagram

What's new in Azure Stack HCI

Windows Admin Center version 2103 adds a number of features and improvements to Azure Stack HCI, including the following:

  • Windows Admin Center updates automatically: Windows Admin Center and extensions now update automatically when a new release is available.

  • Deploy Network Controller using Windows Admin Center: An update to the Cluster Creation extension in Windows Admin Center allows you to set up a Network Controller for Software Defined Networking (SDN) deployments.

  • Use Windows Admin Center in the Azure portal (Preview): Manage the Windows Server operating system running in an Azure VM by using Windows Admin Center directly in the Azure portal. To learn more, see Windows Admin Center in the Azure portal.

  • Event tool redesign (Preview): We’ve redesigned the Events tool for servers and PCs for the first time in ages. To check it out, open the Events tool and then toggle Preview Mode.

  • Install and manage Azure IoT Edge for Linux on Windows: Install, manage, and troubleshoot IoT Edge for Linux on Windows from within Windows Admin Center. To learn more, see Enabling Linux based Azure IoT Edge Modules on Windows IoT.

  • Use a proxy server: Windows Admin Center can now access Azure and the internet through a proxy server. To set up a proxy server in Windows Admin Center, next to Notifications select Settings and then under Gateway select Proxy.

  • Open tools in separate windows: Connect to a system and then on the Tools menu, hover over a tool and select Open tool in a separate window.

  • Virtual machines tool improvements: You can now create your own VM groups in the tool and edit columns. We’ve also made moving a VM easier, allowing you to reassign virtual switches while moving a VM.

For details on the new features and improvements, see Windows Admin Center version 2103 is now generally available.

Clusters running Azure Stack HCI, version 20H2 have the following new features as compared to Windows Server 2019-based solutions:

  • New capabilities in Windows Admin Center: With the ability to create and update hyperconverged clusters via an intuitive UI, Azure Stack HCI is easier than ever to use.
  • Stretched clusters for automatic failover: Multi-site clustering with Storage Replica replication and automatic VM failover provides native disaster recovery and business continuity.
  • Affinity and anti-affinity rules: These can be used similarly to how Azure uses Availability Zones to keep VMs and storage together or apart in clusters with multiple fault domains, such as stretched clusters.
  • Azure portal integration: The Azure portal experience for Azure Stack HCI is designed to view all of your Azure Stack HCI clusters across the globe, with new features in development.
  • GPU acceleration for high-performance workloads: AI/ML applications can benefit from boosting performance with GPUs.
  • BitLocker encryption: You can now use BitLocker to encrypt the contents of data volumes on Azure Stack HCI, helping government and other customers stay compliant with standards such as FIPS 140-2 and HIPAA.
  • Improved Storage Spaces Direct volume repair speed: Repair volumes quickly and seamlessly.

To learn more about what's new in Azure Stack HCI 20H2, watch this video from Microsoft Inspire.

Roles you can run without virtualizing

Because Azure Stack HCI is intended as a virtualization host where you run all of your workloads in virtual machines, the Azure Stack HCI terms allow you to run only what's necessary for hosting virtual machines.

This means that you can run the following server roles:

  • Hyper-V
  • Network Controller and other components required for Software Defined Networking (SDN)

But any other roles and apps must run inside of VMs. Note that you can run utilities, apps, and services necessary for the management and health of hosted VMs.

Video-based learning

The Azure extended network video is here:

Videos about the original, Windows Server 2019-based version of Azure Stack HCI:

Here's a video from a Hybrid Cloud Virtual Event:

Next steps