Update Manager "Scan for Patches" last for 25 minutes

As I wrote at the VMware community forum I encountered problem with the Update Manager which was scanning every host for 25 minutes and the entire remediation process for single host could last even for 1:30h like presented at the print-screen below:

Luckily with a little help of the VMware support I successfully managed to solve this issue.

The case was that the update manager itself was installed more than year and a half ago and it has gigantic repository - dozens of GB and hundreds of patches and bulletins...:)

I was recommend to update all host to 3.5 Update 5a (which breaks all previous patch inheritance) and reinstall the update manager.

It helped and now scanning last for 30 seconds.