After upgrading my Apple Mac Mini to ESXi 5.5 I noticed the following warning message being displayed after joining my ESXi host to my vCenter Server:

"Quick stats on mini is not up-to-date" 

I have seen this warning message in the past and it usually goes away within a few minutes of connecting to a vCenter Server. However, this time it did not go away and as you can see from the screenshot, I have had my ESXi host up for 4 days now and the message is still there.

UPDATE (9/30) - This looks to be a known issue in vSphere 5.5 and there is a permanent fix which has been documented in the following VMware KB 2061008. Restarting the management service will not prevent the warning message from coming again, please refer to the KB for the solution.

I do not know about you, but I like to have a clean environment and I get annoyed when I see warning/error messages in the UI. From what I can tell, vCenter Server was able to collect the "quick stats" from the ESXi host but perhaps there was a communication problem at some point or just a glitch?

In any case, is is pretty easy to fix the problem, you just need to restart the management service on the ESXi host and this will force a refresh of the stats. You have three ways of doing this:

1. Restart management service using DCUI connecting to your ESXi console
2. Restart management service using DCUI via command-line
3. Restart management service using command-line script

Option 1 is pretty straight forward and both Option 2 and 3 can be performed on the command-line via an SSH session to your ESXi host if you have enabled SSH.

Option 2 - To launch the DCUI, just type "dcui" on the command-line and you will be able to interact with the DCUI as you normally would from the console and restart the management service:

Option 3 - To restart just using the command-line, you can run the following command to restrat the management service:

/sbin/services.sh restart