Restoring the NSX Manager connected to an N-VDS switch in a fully collapsed cluster

Products

• VMware NSX

Issue/Introduction

Symptoms:
In a collapsed cluster and when UA is deployed on the N-VDS switch, you experience this symptom:

• When all available UA goes down in a cluster, the N-VDS on the host does not have an active manager. 
• In this situation, to restore the cluster back from the previously collected backup, you cannot deploy a new UA virtual machine and directly attach it to the N-VDS logical switch where the previous UA was connected.

Environment

VMware NSX-T Data Center 2.5.x
VMware NSX-T Data Center

Cause

This issue occurs due to the NSX Manager being in a down state. 

Deployed in a collapsed cluster, meaning the NSX Manager(s) are connected to the NSX VLAN Segments or NSX logical switches on a N-VDS. Network admission control to the NSX networks is controlled by the NSX Manager. When the NSX Manager is down, new virtual machines are not allowed to connect to the NSX networks.

Resolution

To resolve this issue, manually restore the fully Collapsed vSphere Cluster. For more information, see the Restore a Fully Collapsed vSphere Cluster Manually section of the VMware NSX-T Data Center 2.5 Installation Guide.