We purchased a Tripp Lite SmartOnline UPS device to use for our entire server rack. We have 12 Dell servers, so they communicate with the UPS using a SNMP card in the UPS. Using a shutdown agent provided by Tripp Lite, I can gracefully shutdown the servers while on battery power.
Tripp Lite support told me that the servers should come back up when power is restored. This is true IF the server did not get shutdown gracefully. However, if the OS did unload and shutdown the hardware properly (which is, of course, the way we want it), the server does not "know" it should restart -- it is in the same state it would be in if I had used "start/shutdown".
Tripp Lite doesn't seem to have any suggestions for getting servers restarted.
Can anyone suggest to a strategy using the SNMP card in conjuction with wake on lan functionality of the servers? Perhaps some code to recieve snmp calls and then send WOL packets to the servers' NICs after the UPS is on AND no longer on battery?