We had a problem last week in which our APC UPS apparently didn't behave as expected and desired. There was a short (under 5 minutes) power outage last Tuesday night; the UPS shows 16 mins. of runtime at full load. So the UPS should have kept the 4 ESX hosts and the 2 Windows servers up & running with no issues. But when we retuned the next day, each server displayed the Windows screen asking for a reason why the server was abruptly shut down.
So it looks like one of two things happened: Either the UPS didn't have the battery charge we thought it had, and there was not enough time for the PowerChute Network Shutdown (PCNS) software to gracefully down the servers before everything lost power. Or the battery was sufficiently charged, and the PCNS is not configured to quickly shut down the OSes, or otherwise in some way failed to shut down the OSes as it should have prior to the battery being discharged.
So now I need to test both scenarios. I plan to test the UPS battery runtime without compromising an OS by shutting down the OSes and leaving the servers powered up. Then I'll disconnect wall power from the UPS and see how long the servers stay powered up before they die. Once I've done the first test and confirmed how long the battery will keep the rack up and running, then I'll move on to ensuring that the shutdown software works as configured and actually begins the shut down process on the running VMware and Windows OSes once the UPS has been on battery for about 60 seconds.
So I know how to down all the VMs on these hosts. Here's my question:
What is the VMware command to shut down the OS without shutting down the hardware? I want the VMware servers to still be powered up, but without the OS being vulnerable to an abrupt power loss.