Dell EMC Solutions for Azure Stack HCI offers stretched cluster solutions with AX nodes from Dell Technologies. Built using industry-leading PowerEdge servers, AX nodes offer fully validated HCI nodes for a variety of use cases. A robust set of configurations and different models allows you to customize your infrastructure for application performance, capacity, or deployment location requirements.
Stretched clusters and Storage Replica
An Azure Stack HCI stretched cluster solution is a disaster recovery solution that provides an automatic failover capability to restore production quickly, with little or no manual intervention. Storage Replica, a Windows Server technology, enables replication of volumes between servers across sites for disaster recovery. For more information, see Storage Replica overview.
A stretched cluster with Azure Stack HCI consists of servers residing at two different locations or sites, with each site having two or more servers, replicating volumes either in synchronous or asynchronous mode. For more information, see Stretched clusters overview.
A stretched cluster can be set up as either Active-Active or Active-Passive. In an Active-Active setup, both sites will actively run VMs or applications; therefore the replication is bidirectional. In an Active-Passive setup, one site is always dormant unless there is a failure or planned downtime.
Sites can be on the same campus or in different places. Stretched clusters using two sites provides disaster recovery if a site experiences an outage or failure.
The following figure shows an Active-Active setup:
Sites can be logical or physical. For logical sites, a stretched cluster can exist on single or multiple racks or in different rooms in the same data center. For physical sites, the stretched cluster can be in different data centers on the same campus or in different cities or regions. Stretched clusters using two physical sites provide disaster recovery and business continuity should a site suffer an outage.