You can add ESXi hosts to a running vSAN cluster without disrupting any ongoing operations. The new host's resources become associated with the cluster.
Prerequisites
- Verify that the resources, including drivers, firmware, and storage I/O controllers, are listed in the VMware Compatibility Guide at http://www.vmware.com/resources/compatibility/search.php.
- VMware recommends creating uniformly configured hosts in the vSAN cluster, so you have an even distribution of components and objects across devices in the cluster. However, there might be situations where the cluster becomes unevenly balanced, particularly during maintenance or if you overcommit the capacity of the vSAN datastore with excessive virtual machine deployments.
Procedure
What to do next
Verify that the vSAN Disk Balance health check is green. If the Disk Balance health check issues a warning, perform a manual rebalance operation during off-peak hours. For more information, see "Manual Rebalance" in vSAN Monitoring and Troubleshooting.
For more information about vSAN cluster configuration and fixing problems, see "vSAN Cluster Configuration Issues" in vSAN Monitoring and Troubleshooting.