Modify vDS associated to logical switches in an NSX prepared cluster

Products

• VMware NSX

Issue/Introduction

If a new vDS is created and existing NSX logical switches need to be deployed to the new vDS, you must modify the existing configuration or create a new cluster with the new settings.

Environment

VMware NSX for vSphere 6.x

Resolution

The vDS associated to an NSX prepared cluster is defined ruing the "configure VXLAN" step. See Configure VXLAN Transport Parameters

In order to modify the vDS in a NSX prepared cluster, there are 2 alternatives:

1. Create a new cluster
   
   
   1. Migrate at least one host to the new cluster
   2. Verify that the host you migrated has been added to the new VDS
   3. Install NSX VIBs
   4. Configure VXLAN using the new vDS
   5. Add the new cluster to the transport zone
   6. Progressively migrate VMs and hosts to the new cluster. Notice that you will need to put hosts in maintenance mode, take them out of the clusters to the Data Center inventory level and then add them to the new cluster.
      
      
2. Unconfigure VXLAN
   
   
   1. Disconnect all VMs from all logical switches or vMotion all VMs connected to logical switches to a different cluster.
   2. Disconnect the cluster from the transport zone: Installation / Logical Network Preparation / Transport Zones / Disconnect clusters (cluster icon with a pencil).
   3. Unconfigure VXLAN: Installation / Host Preparation / Click on cluster / Actions / Unconfigure VXLAN. This will remove the VXLAN VMKernel port and all associated logical switch port groups from the current VDS.
   4. Configure VXLAN again, this time select the new vDS.
   5. Connect the cluster to the transport zone again.

Alternative number 1 has less impact as it allows the administrator to do a progressive migration of the VMs possibly without downtime (this depends on the amount of hosts/resources available).

Additional Information

Impact/Risks:
Network outage for VMs in the affected hosts/clusters.

Prepare Host Clusters for NSX