Migrating a vSAN node from one vSAN cluster to another vSAN cluster

Products

• VMware vSAN

Issue/Introduction

Symptoms:

This content provides steps to migrate a vSAN Node from one vSAN cluster to another vSAN cluster with the virtual machines residing on the node going to migrate.

Environment

VMware vSAN 6.x
VMware vSAN 7.x
VMware vSAN 8.x

Resolution

Perform the following steps to migrate a vSAN Node from one vSAN cluster to another vSAN cluster:

1. Put the Host in maintenance mode with Full Data Migration.
2. Once the host is in maintenance mode, delete the disk groups on that host.
3. Through SSH or ESXi shell, run the below command to leave the host from the existing cluster:
   
   esxcli vsan cluster leave
    
4. Right click on the ESXi Host > Connection > Disconnect.
5. Drag and drop the disconnected host into the new cluster.
6. Right click on the ESXi Host Connection > Connect.
   
   Note: This step connects the ESXi host back to vCenter.
    
7. Open an SSH session to any existing host in the new cluster. Run the below command to get the Sub-Cluster UUID:
   
   esxcli vsan cluster get
   
   In the output make a note of the Sub-Cluster UUID.
   
   Example:
   
   [root@IS-EVO-02:~] esxcli vsan cluster get

Cluster Information

Enabled: true

Current Local Time: 2017-05-12T07:58:40Z

Local Node UUID: ########-####-####-####-########23ab

Local Node Type: NORMAL

Local Node State: MASTER

Local Node Health State: HEALTHY

Sub-Cluster Master UUID: ########-####-####-####-########23ab

Sub-Cluster Backup UUID:

Sub-Cluster UUID: ########-####-####-####-########0664

Sub-Cluster Membership Entry Revision: 0

Sub-Cluster Member Count: 1

Sub-Cluster Member UUIDs: ########-####-####-####-########23ab

Sub-Cluster Membership UUID: ########-####-####-####-########adc0

Unicast Mode Enabled: true

Maintenance Mode State: ON
    
8. Open an SSH session to the newly added host and run the below command to add the host to the new vSAN cluster :
   
   esxcli vsan cluster join -u "<sub-cluster uuid>"
   
   Here, <sub-cluster uuid> is the Sub Cluster UUID obtained from Step 8.
   
   Note: Now, the ESXi host is part of the new cluster.
    
9. Recreate the Disk groups on the newly added host.
10. If required to migrate other hosts, follow Steps 2 through 9 on the remaining hosts.