My concern is that I have experienced (more than once) a complete loss of UPS feed when a UPS goes to bypass due to an internal fault and the STS does not fall over to the reserve (secondary) UPS. This is mostly an issue at colos since I don’t control the design – some don’t use an STS and rely on gens for feed when a UPS goes to bypass. When this occurs and the BitSight is powered by that string, I will lose all data from the sensors on that Bitsight. We used to have this issue with Cyclades remote console systems – they’ve addressed the problem by having dual power inputs on their gear now. If I am to rely on Ravica units as a part of my enterprise monitoring system, and if they are to be considered critical systems, they need similar redundancy. I’m just sayin…..

Really, you can have the BitSight getting power from anywhere you want. It can be the same UPS the sensors are monitoring or a different one all together. If there is an emergency life line string then throw it on that. The point of having a BitSight in place to monitor your UPS is more to know when you are using battery backup vs. line voltage, not when your UPS is failing. Ideally the Ravica systems in place have already notified you that you are running on limited battery life well before the UPS is drained.

The fact of the matter is, if your BitSight is on an emergency life line string and the UPS supplying its power goes down, then any systems that it would use to alert you (e.g. web servers, mail servers, VoIP servers, etc.) are going to be without power as well. Which would make keeping the BitSight online a moot point.

But like I said, the real idea here is to be proactive and get the alerts well in advance that say, “Hey, your power went out and you are on battery backup. Time to shut non essential systems down and keep business critical apps running for as long as possible.”

Hope that offers some additional insight.