"Host OS not found" error when uninstalling NSX-T Data Center 2.x and later versions

Products

• VMware NSX

Issue/Introduction

Symptoms:

• Uninstalling NSX-T Data Center 2.x and later versions fail.
• In the /var/log/proton/nsxapi.log file, you see an error similar to:
  
  ERROR ActivityWorkerPool-1-1 DeploymentUnitActivityUnInstall - FABRIC [nsx@6876 comp="nsx-manager" errorCode="MP26050" level="ERROR" subcomp="manager"] Host unprep failed for 3b02XXXX-XXXX-XXXX-XXXX-XXXXXX980f.
  Error :
  Host OS version not found.
   
• In the User Interface (UI), you see entries similar to:
  
  Failed to uninstall software on host. Host OS version not found.
  
  Note: The preceding log excerpts are only examples. Date, time, and environmental variables may vary depending on your environment.

Environment

VMware NSX-T Data Center 2.x
VMware NSX-T Data Center 3.x

VMware NSX 4.x

Cause

This issue occurs when a user tries to uninstall NSX immediately after installing NSX. The Agent installed as part of NSX preparation can take few minutes to report the OS version of the host.

Resolution

To resolve this issue, retry the uninstall operations after a few minutes. Wait until the host OS version is reported by the agent as installed as part of the NSX install.

Note: The API to check the OS version of a transport node is:

GET https://<NSXMGR_IP>/api/v1/transport-nodes/<TN-ID>