A while ago, I purchased a used IBM server that has been a very nice tool. Here’s the specs:
I have it hooked up to a battery backup unit, which is connected with the USB cable. When the power goes out for a length of time, it powers the machine into a strange state that I cannot get it out of. The light on the front turns orange, and none of the buttons will reboot it. I have to pull the power cord and wait for it to power down. When I plug it back in, it works fine.
I found that the server does have a BMC built in that is supposed to allow for remote power control. There are several IPMI clients that I can install in Linux that should be able to control it. I was able to set the IP address for the console as well use the username and password in the BIOS of the machine.