Recently I have upgrade VMware clusters from version 6.0 to 6.5. Upgrading went smoothly but I noticed that the ESXi hosts were not in maintenance mode (mm) in SCOM.
Setup: MS SCOM, Veeam Management Pack for System Center. Other ESXi hosts managed by another vCSA were not causing this issue.
After some investigation by Veeam Support the root cause was found. The different versions of ESXi before and after the upgrade was causing the issue.
The solution was easy and straight forward. Clearing the SCOM agent cache on all the Veeam Collector(s) and Veeam Enterprise Server (VES) and “Rebuild the full topology” in the Veeam VES management webpage. How long it takes to rebuild depends on the size of your environment. I have waited a few hours and put an ESXi host in maintenance mode and back out of maintenance. Everything works as usual.
by Vincent