Stretching vSAN Clusters in VMware Cloud
Foundation
You can stretch a vSAN cluster in a
workload domain across two availability zones within a region. Both availability zones must
contain an equal number of hosts to ensure failover in case any of the availability zones
goes
down.
The default management vSphere cluster must be
stretched before a VI workload domain cluster can be stretched. This ensures that the
NSX
control plane and
management VMs (vCenter, NSX
management cluster, and SDDC Manager) remain accessible if the
stretched cluster in the primary availability zone goes down.You cannot stretch a cluster in the
following conditions:
- The cluster uses static IP addresses for theNSXHost Overlay Network TEPs.
- The cluster has a vSAN remote datastore mounted on it.
- The cluster uses vSphere Lifecycle Manager images.
- The cluster shares a vSAN Storage Policy with any other clusters.
- The cluster is enabled for Workload Management (vSphere with Tanzu).
Some use cases for stretching a cluster are described
below.
- Planned maintenanceYou can perform a planned maintenance on an availability zone without any downtime and then migrate the applications after the maintenance is completed.
- Automated recoveryStretching a cluster automatically initiates VM restart and recovery, and has a low recovery time for the majority of unplanned failures.
- Disaster avoidanceWith a stretched cluster, you can prevent service outages before an impending disaster.