We have a Riello UPS system for our server room and I have my shutdown script in place to be able to gracefully shut down all the servers/hosts and telephony equipment. For the other equipment that doesn’t have a shutdown option I have managed PDU’s to allow me to power those down.
We have enabled the AC Power Recovery setting on in the Bios. These are Dell PowerEdge’s (mix of older models and newer)
Some legacy small UPS’s are in the rack still plugged into the 2nd PSU’s of a lot of the servers. But to try negate that as causing any issue we are going to put them into Bypass mode.
So basically my question is, say we have a power cut and all the servers get shutdown gracefully as per the script but the power comes back on before the UPS is totally drained. Once the power comes back on, I am guessing that I will have to get the PDU’s to cut off and then power on for the servers to detect this and the BIOS setting to allow them to power back on. Or would the fact that the small UPS’s, being in bypass mode, when that power comes back on would it be sufficient to alert them to power back on?
Any suggestions/others experience on this would be appreciated.
I appreciate though the only way to be sure is to try it out, but I want to try get as much info as I can before I attempt it.