VMwre ESXi 5 - Hardware Health Status shows "Unknown"

Log onto the console and run /sbin/services.sh restart

Also, please update the ESXi version if you can. It's an old revision and you may be running into a bug/deficiency that's been resolved in a later version.

I have a Cisco UCS-C240 server that runs ESXi 5.5 U2 to run 2 VMs, an standalone host, no vcenter (so almost the same problem).

I opened a ticket in VMware and after a webex the solution was:

1-Log via SSH to the host.

2-Run the following commands:

 ~ # localcli hardware ipmi sel clear
 ~ # /etc/init.d/sfcbd-watchdog restart

3-Click the Reset Sensors button.

Everything should be ok.

Here is a link to the VMWare solution:

https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1033725