Permanently Decommissioning a node from a vSAN Cluster

Products

• VMware vSAN

Issue/Introduction

Procedure to decommission a vSAN node.

Environment

VMware vSAN 7.x

VMware vSAN 8.x

Resolution

Following the correct procedure is crucial when permanently decommissioning a vSAN node. If the disk groups are left behind or the node is not disassociated with the cluster, residual components can be left behind which can have an impact on cluster stability.

 

1. Ensure that there is no resync running on the vSAN cluster before starting the activity.
2. Ensure there is sufficient capacity in the vSAN disk groups to decommission a node.
3. Ensure the number of remaining nodes in the vSAN cluster post decommissioning a node is compliant with the current storage policy if not change the current storage policy to be compliant with the remaining nodes in the vSAN cluster.
4. Right click on the host which is to be decommissioned > Maintenance mode > Enter Maintenance mode > Pre-check.
5. This pre-check simulates what the cluster would look like if it is not contributing to the vSAN cluster. From the pre-check results:
   1. Verify that none of the vSAN objects go in reduced availability or inaccessible state.
   2. Verify that there is enough space in the cluster.
6. Once verified that all is green, put the host into maintenance mode with full data migration selected. This will evacuate all disk groups on the host.
7. Wait for resync traffic to complete and the host to enter maintenance mode.
8. For vSAN OSA after the host is in maintenance mode delete the disk group(s) that reside on the host you want to decommission:
        Select the vSAN cluster > Configure > Disk Management > Select the host to be decommissioned > View Disks > Select the disk group >Remove the Disk group
   For vSAN ESA remove the disks that reside on the host you want to decommission:
        Select the vSAN cluster > Configure > Disk Management > Select the host to be decommissioned > View Disks > Select the disks > Remove Disk
9. Move the ESXi host out of the cluster to disassociate it from vSAN
   Note: The command esxcli vsan cluster leave can also be run from the command line of the host to leave the cluster
10. Shutdown the ESXi host.

To fully disable a vSAN cluster, see Disable vSAN.

Note: To decommission a vSAN node that has failed in a vSAN cluster engage vSAN support for further assistance.

Additional Information

To perform maintenance mode pre-check for ESXi host: Check a Host's Data Migration Capabilities

vSAN Storage Policies Using vSAN Policies