NSX Management Plane Upgrade stuck at 70%

Products

• VMware NSX

Issue/Introduction

• NSX Manager upgrade is stuck at 70% in the UI for the affected NSX manager node
  
• The command 'get service install-upgrade' on the affected NSX Manager shows the error message below:
  

  Upgrade info:
From-version: 4.2.2.1.0.24765087
To-version: 4.2.3.3.0.25171321

  Upgrade steps:(Timelines)
download_os [2025-10-16 13:36:32 - 2025-10-16 13:36:57] SUCCESS
shutdown_manager [2025-10-16 13:47:10 - 2025-10-16 13:48:40] SUCCESS
install_os [2025-10-16 13:48:40 - 2025-10-16 13:49:36] SUCCESS
migrate_manager_config [2025-10-16 13:49:37 - 2025-10-16 13:49:42] SUCCESS
pin_ui [2025-10-16 13:49:42 - 2025-10-16 13:49:47] SUCCESS
switch_os [2025-10-16 13:49:47 - 2025-10-16 13:49:48] SUCCESS
reboot [2025-10-16 13:49:48 - 2025-10-20 07:17:15] SUCCESS
start_manager [2025-10-17 05:16:42 - 2025-10-17 05:18:18] FAILED <-----------*************

  ------ Output of last step start ------

  Status:

  wait_for_proton: resp_status: HTTPStatus.INTERNAL_SERVER_ERROR, body: None

  Stdout: Removed /config/.resume_upgrade flag

  Starting start_manager upgrade script

  Creating /.eula/.eula_accepted.txt.

  Migrated /os/bak/.eula/.upgrade_eula_accepted.txt to /.eula/.eula_accepted.txt successfully.

  Setting file permissions for eula

  Removing eula.txt

  Proton service did not start within the allotted time.
  
  

• The option to retry the upgrade is not available in the UI
• The NSX Manager is not responding to pings
• ifconfig on the NSX manager does not show the eth0 interface, only loopback is seen
  
• Attempts to bring up the interface using the command ifup eth0 show that the IP address/netmask  has "//" as shown in the error below
  

  root@nsxmanager:~# ifup eth0

  Error: any valid prefix is expected rather than "#.#.#.#//##".

  ifup: failed to bring up eth0

Environment

VMware NSX 4.2.x

Cause

• The Proton service did not start because the affected NSX Manager is unable to reach other NSX Managers within the cluster.
• The eth0 interface on the NSX manager is not coming up because the IP address has an invalid netmask prefix (//) - "#.#.#.#//##"

Resolution

Workaround: 

• To complete the upgrade process, reconfigure the IP address of the NSX manager with the commands below to make it reachable over the network:
  ifconfig eth0 #.#.#.# netmask #.#.#.#
route add default gw #.#.#.#
• Once upgrade is complete, redeploy all the affected NSX managers using the correct subnet mask syntax by following the steps in Replace a manually deployed NSX Manager node

Additional Information