Stretched clusters in Azure Local, version 22H2 (formerly Azure Stack HCI, version 22H2) entail a specific technical implementation of storage replication that spans a cluster across two sites. Azure Local, version 23H2 has evolved from a cloud-connected operating system to an Arc-enabled solution with Arc Resource Bridge, Arc VM, and AKS enabled by Azure Arc. Azure Local, version 23H2 expands the requirements for multi-site scenarios beyond the OS layer, while Stretched clusters do not encompass the entire solution stack.
Based on customer feedback, the new Azure Local release will replace the Stretched clusters defined in version 22H2 with new high availability and disaster recovery options.
For Short Distance
Rack Aware Cluster is a new cluster option which spans two separate racks or rooms within the same Layer-2 network at a single location, such as a manufacturing plant or a campus. Each rack functions as a local availability zone across layers from OS to Arc management including Arc VMs and AKS enabled by Azure Arc, providing fault isolation and workload placement within the cluster. The solution is configured with one storage pool to reduce additional storage replication and enhance storage efficiency. This solution delivers the same Azure deployment and management experience as a standard cluster. This setup is suitable for edge locations and can scale up to 8 nodes, with 4 nodes in each rack. Rack Aware Cluster is currently in private preview and is slated to public preview and general release in 2025.
For Long Distance
Azure Site Recovery can be used to replicate on-premises Azure Local virtual machines into Azure and protect business-critical workloads. This allows Azure cloud to serve as a disaster recovery site, enabling critical VMs to be failed over to Azure in case of a local cluster disaster, and then failed back to the on-premises cluster when it becomes operational again. If you cannot fail over certain workloads to cloud and require long distance of disaster recovery, like in two different cities, you can leverage Hyper-V Replica to replicate Arc VMs to the secondary site. Those VMs will become Hyper-V VMs on the secondary site, they will become Arc VMs once they fail back to the original cluster on the first site.
Additional Options beyond Azure Local
If the above solutions in Azure Local do not cover your needs, you can fully customize your solution with Windows Server 2025 which introduces several advanced hybrid cloud capabilities designed to enhance operational flexibility and connectivity across various environments. Additionally, it offers various replication technologies like Hyper-V Replica, Storage Replica and external SAN replication that enable the development of tailored datacenter disaster recovery solutions. Learn more from the Windows Server 2025 now generally available, with advanced security, improved performance, and cloud agility - Microsoft Windows Server Blog
What to do with existing Stretched clusters on version 22H2
Stretched clusters and Storage Replica are not supported in Azure Local, version 23H2 and beyond. However, version 22H2 stretched clusters can stay in supported state in version 23H2 by performing the first step of operating system upgrade as shown in the following diagram to 23H2 OS. The second step of the solution upgrade to Azure Local is not applicable to stretched clusters. This provides extra time to assess the most suitable future solution for your needs.
Please refer to the About Azure Local upgrade to version 23H2 - Azure Local | Microsoft Learn for more information on the 23H2 upgrade.
Refer the blog on Upgrade from Azure Stack HCI, version 22H2 to Azure Local | Microsoft Community Hub.
Conclusion
We are excited to be bringing Rack Aware Clusters and Azure Site Recovery to Azure Local. These high availability and disaster recovery options allow customers to address various scenarios with a modern cloud experience and simplified management.
Microsoft