Does anyone know if it's possible to configure a vCenter 5 alarm to monitor the loss of PSU redundancy of a host? I'm looking through the options to configure alarms and the Power State alarms on the Host portion only seem to monitor whether the host is powered on, powered off or in Standby mode.
Am I looking in the wrong place or is this even possible?
For the most part, this will work out of the box. vCenter will send an SNMP trap on "Host Power Status". You can change that to an email alert...
You mentioned that you're using Dell hardware. First, make sure you install the Dell CIM agents/update for ESXi to provide proper insight into your specific server's hardware.
From there, you can check to see that your server posts power supply status under the "Hardware Status" tab in the vSphere Client.
If I pull the power supply, I get:
For alerts, there's a default alarm for "Host hardware power status" defined in your Virtual Center > Alarms > Definitions. To receive an email for this, just modify the "Actions" tab.
There's actually a default alarm for this, "Host hardware power status".
The PSU status is monitored as part of the host's hardware health, so that's the type of alarm you'd need to define (assuming that your hardware supports being monitored through the vCenter Hardware Status tab).
For example, here's what the triggers look like for that default alarm:
