Transport Node Profile (TNP) Not Applied After NVDS to CVDS Migration

Products

• VMware NSX

Issue/Introduction

• During an NSX-T NVDS (N-VDS) to CVDS (vSphere Distributed Switch) migration, the Transport Node Profile (TNP) is typically applied to the hosts after the final host in the cluster successfully migrates.
• However, an issue has been observed where, if the migration process is interrupted (e.g., due to failures on some hosts requiring remediation) and subsequently re-triggered by deleting the previous pre-check and re-running the topology, the TNP is not applied to the migrated hosts at the completion of the process.

 

Environment

VMware NSX

Cause

• When an NSX-T NVDS to CVDS migration is initiated, the relevant Transport Node Profile (TNP) configuration is stored within the migration context.
• If the migration encounters issues, requiring the user to delete the previous pre-check and re-run the topology (which is a common troubleshooting step for re-triggering migration), this action inadvertently clears the migration context.
• As a result, the TNP information, which was intended to be applied at the end of the migration for the last host, is no longer retained.
• Consequently, upon successful completion of the re-triggered migration, the hosts are left without the desired TNP applied.
  
  

• Question: Why was the TNP not recreated in the migration context during the subsequent Precheck?

  Answer:
  As part of the migration workflow, the TNP is detached during the migration of the first host and replaced with a CVDS-compatible TNP at the end of the process.

  When the cluster contains a mixed set of hosts (with some on NVDS and others on CVDS ) a common TNP cannot be applied. As a result, during the subsequent precheck, the cluster is found without a valid TNP. Therefore, no TNP configuration is included in the migration context.

Resolution

If you encounter this scenario where the TNP is not applied after re-triggering an interrupted NVDS to CVDS migration:

Manually create &  apply the desired TNP, ensuring it matches the host configuration in the cluster at the end of the NVDS to CVDS migration.