vCenter is stuck when Refreshing The Page/Migrating VMs/Converting VM to a template

Products

• VMware vCenter Server

Issue/Introduction

vCenter is stuck for at least 15 seconds or the page is not responding every time you are:

• Refreshing the page 
• Converting a VM to a template
• Moving VMs to another folder
• You are presented with the message: "This page isn't responding"

• You can also experience the message below even after the 3rd party client plugins that are not in use anymore, are being unregistered

Note: 

• The UI works well when cluster view is not expanded in Host and Cluster view

Environment

vCenter Server 8.x

vCenter Server 7.x

VMware vSphere 8.x

VMware vSphere 7.x

Cause

• You have a large number of VMs under the cluster, which causes UI performance issues

Resolution

Workaround:

• The recommendation in this case is to hide the VMs in the Host and Cluster inventory tree.
• This can be done by opening the 'My Preferences' dialog and disabling the option "Show VMs in Hosts and Clusters view" in the Inventory tab.
• Additionally, in this case, the VMs should be grouped in VM folders. The idea is that when there are a large number of VMs under the cluster, not all of them to be rendered at once when the Inventory tree is rendered in the browser.

Note:

• If you navigate to the VMs & VM Templates inventory tree and you expand all VM folders, leaving them all expanded, the UI will start to hang again.
• If you open UI from a VM that does not have enough CPU it will cause slowness as well.  In this case you can access the UI directly from a machine with sufficient CPU or from another VM configured with a larger CPU, to test whether there will be a difference in the UI behavior.