vCenter task "Download Patch Definitions" frequently gets stuck.

Products

• VMware vCenter Server

Issue/Introduction

• You notice that the vCenter task Download patch definitions frequently gets stuck at 10%.
• When the task doesn't get stuck at 10%, it complete successfully

Environment

vCenter 8

Cause

A vCenter certificate refresh caused vSphere Update Manager (VUM) to have an exception that left the VUM Inventory Monitor in a bad state. Each subsequent scheduled Download patch definitions would cause 4 Download patch definitions tasks to run, which would conflict with each other. Only a single Download patch definitions can run at once and the remaining tasks will get stuck. 

Resolution

Restart the VUM service by establishing an ssh session to the vCenter server and running the following command:

vmon-cli -r updatemgr

After VUM is restarted, a new VUM Inventory Monitor will be created and will launch a single Download patch definitions task to run going forward.

Additional Information

If you notice that the Download patch definitions scheduled task is no longer running after applying the resolution, verify its schedule:

1. Navigate to: vSphere Client Menu > Lifecycle Manager > Settings tab.
2. If vCenter is in linked mode: Select the correct vCenter.
3. Go to Administration > Patch Downloads and click Edit.
4. Confirm that the Download Schedule is set to a future date/time.