I have a rather simple UPS (Powerwalker VI series) that does not seem to have any sophisticated built-in configuration options. When the power is cut and servers detecting that event shut down after a while, servers stay powered off.
What I need is starting them up automatically once the power is restored and say 5 minutes pass to ensure this is not a fluke.
Is there a way to achieve this using just servers and/or USB link (from UPS to servers)?
P.S. I was not precise enough, the scenario is as follows:
After a period of offline power, servers shut down. However, UPS does not cut power off, probably not until the batteries are totally exhausted. This takes time, since the power consumption of a server that is shut down is obviously minimal, just enough to power functions like WOL and IPMI subsystem. Since I can't take servers offline for like say 3 days, I can't even test this.
Since power is not cut off at UPS, the servers do not "know" about the power loss and do not power up after power is restored. Therefore, if power is lost for like say 1-2 hours, the servers stay shut (and unfortunately there is nobody around to power them up).