Merging vSAN clusters. pt3

Move hosts from vCenter B, cluster B to vCenter A, temporary cluster.


  • I have two separate vCenter Servers.
  • Each has a vSAN cluster.
  • Each cluster is connected to additional separate storage.
  • Each cluster is on a different IP range, different naming convention and different domain.
  • Hosts in each cluster are identical in spec, reside in the same rack and are physically connected to the same e/w & n/w switches.
  • vCenter & ESXi hosts are on 6.0u3 with latest patches with embedded PSC.


  • Create one cluster with all hosts & one vSAN datastore, one vDS.
  • Decommission one vCenter server.
  • Decommission one of the external storage devices.


  1. Export the vDS config on vCenter B and import to vCenter A.
  2. Decommission vSAN cluster on cluster B.
  3. Move hosts from vCenter B, cluster B to vCenter A, temporary cluster.
  4. Re-ip & rename hosts to match hosts in cluster A.
  5. Add hosts into vSAN cluster A.
  6. Merging Distributed Virtual Switch.

3. Move hosts from vCenter B, cluster B to vCenter A, temporary cluster.

Disconnecting host from old vCenter.

Right click host – connection – disconnect.

Remove Host from Inventory.

Right click disconnected host – Remove from inventory. (this take a few minutes)…

During this process VM’s should not lose connectivity, you are simple moving the host to be manged by a different vCenter Server, all physical networking is obviously still in place.

Step 4.

Add the host to the new vCenter.

Enter FQDN or IP address and enter username and password for ESXi root account, (hoping you tested the credentials worked before hand).

Add the hosts to the cluster.

You will notice a warning on the host mentioning a host proxy switch, this is due to the host not being associated to the newly import vDS.

Keep an eye on your continuous ping you have running to your vm’s associated host.

Step 5.

Add your host to the vDS.

Go to Networks, locate the new switch, right click and click Add and Manage Hosts…

Select – Add host and manage host networking (advanced)

Click add hosts, as the host is not attached to the vDS yet.

Select Manage Physical adapters, Manage VMkernel adapters, Migrate virtual machine networking.

Select uplinks.

Assign portgroups (its good to have screenshots of how it was setup just in case), plus an RVTools export.

Everything on a standard switch will stay with the hosts.


I kept an eye on continuous ping and noticed a millisecond of a drop.

Enabled network health check for my test and got vlan and mtu issues.