How to convert a vSAN Stretch cluster to a Standard Cluster while decommissioning the Secondary site.

Products

• VMware vSAN

Issue/Introduction

This KB provides steps for converting a Stretch cluster to a Standard cluster and then decommissioning the hosts from the Secondary Site from the cluster.

Environment

VMware vSAN (All Versions)

Resolution

The below steps assume there is plenty of free space on the vSAN datastore to accommodate production without impact. If the vSAN datastore is low on space do not try these steps until space is freed up. 

1. Create a None - keep data on Preferred (stretched cluster) storage policy to keep all data on the Preferred site.
   
   
2. Apply the policy to all VMs in the environment
   Note: To avoid any production impact apply the policy to VMs a few at a time, don't apply the policy to all VMs simultaneously 
   
   
3. Set the storage policy for the .vsan.stats object to the Storage policy created in Step 1 via Cluster > Configure > vSAN > Services > Performance Service click Edit
   
   
4. Disable the stretch cluster via Cluster > Configure > vSAN > Fault Domains and select "Disable Stretched Cluster"
   
   
5. Follow KB Permanently Decommissioning a node from a vSAN Cluster to remove the hosts in the secondary site from the cluster. This will simultaneously remove the Secondary Fault domain.
   
   
6. Via Cluster > Configure > vSAN > Fault Domains > select all the hosts in the Preferred Fault Domain, select the 3 stacked ellipses in the upper right of the fault domain and chose remove from Preferred. This will move all the hosts into their own respective standalone fault domain.
   
   
7. Set all VMs and the .vsan.stats to the vSAN Default Policy or what ever policy required for your environment/production needs
   Note: To avoid any production impact apply the policy to VMs a few at a time, don't apply the policy to all VMs simultaneously 
   
   
8. Go to Cluster > Monitor > vSAN > Resyncing Objects and confirm the objects are resyncing to the new applied policy. If the objects are sitting in the "Scheduled resyncing" click on Repair/sync now
   
   
9. Set the vSAN datastore storage policy to a storage policy for your required environment/production needs ensuring it's not set to a stretch cluster aware storage policy, via Datastores > <vSAN Datastore> > Configure > Default Storage Policy and click Edit

Note:

• After completing the above steps if there should be any objects in an unhealthy state then we're dealing with objects the vCenter UI is unaware of. Follow KB Procedures for identifying Unassociated vSAN objects to check for any potential unassociated objects. Review the list to determine if any of the objects can be safely deleted from the environment. 
  
  
• If there are snapshots in use by the VMs, consolidate them and then change the vSAN storage policy as per Step 2. If the snapshots are required kindly reach out to Broadcom support for assistance - vSAN Support.