CLI based NVDS to DVS migration failed with the list of transport nodes

Products

• VMware NSX

Issue/Introduction

Failed migration of NVDS to DVS

The migration process brought one of the hosts into maintenance mode but NVDS was not migrated to DVS. The host remained in maintenance mode. 

Environment

VMware NSX-T 3.1.x

VMware ESXi 7.0.3

Cause

Procedure to migrate NVDS to DVS is listed in the following document.  
https://docs.vmware.com/en/VMware-NSX-T-Data-Center/3.1/administration/GUID-1039A36F-F55E-4A0A-B6C6-2C383F4A716D.html

Command line execution of the procedure resulted into error condition.

Following error message was logged in /var/log/nsx-cli/nsxcli.log

"Transport-Nodes Migrate Failed.ID list {'<UUID>' : 'GetVCMode: {"external_id" : <UUID>", "ip_addresses" : {"x.x.x.x", .......]

One of the NSX T edges managed by this NSX manager was in maintenance mode. The issue can also be caused if the edge is displaying Mismatch alarm.

Resolution

The edge was brought out of maintenance mode and the migration was successful. 

Additional Information

Migration requires NSX T edges online in healthy state.