Happened friday morning: I was in one of our off-site sever rooms, installing our new Zabbix sever (yes, 1.8.4 is really coming alive in april!), and adding some power supplies to another server. Several minutes later I got a phonecall about the server with the added psu's:
Zabbix delivered a text message, sever was unreachable. I checked and indeed, it was powered down, apparently I pushed the power button when sliding back the sever. So, quick zabbix critical message, quick power on, downtime minimized. Ooooooopssss...!