By the way I want to correct myselft about something I said to Mirfster:"...this NUT , which I am not very familiar with..."
Actually I do remember this dead horse I just forgot about it. My days trying to use it for shutting down multiple PC are fortunately behind me.
For anybody who don't know what NUT is let me do quick Q and A on the subject to help anybody who is confused:
(this is based on APC UPS's, can't speak for other manufactures implementation)
Q: What is NUT ?
A:Is 3th party software software based mostly on reversed engineered drivers that attempt to control your ups unit to shutdown multiple PC's.
Q: How that works ?
A: You need another machine that will run this service and if the machine don't crash and was able to read from the ups will send signal to other machines to shutdown.
Q:What is the most reliable way to shutdown a single machine with apc ups ?
A: USB cable
Q: Do I need software for using USB method ?
A: NO, It''s recognized from most OS. Software is optional and will give you additions feature , but totally unnecessary for basic functions.
Q:Will this work it network crash ?
A: No, it's independent from the network cause your UPS has direct connection to the server.
Q: Why then everybody is using USB if it's so simple and easy.
A:When you have more than 1 machine that needs to be shutdown with only 1 ups, you will need other solution.
Q:How then I can shutdown multiple machines using apc UPS ?
A:You need NMC Card for the supported ups models.
Q: What is APC saying about this solution for multiple machines ?
A: APC official and only solution is NMC card.
Q:Is it reliable ?
A: Is the most it can be. It relies on the network to talk to the ups , but is not relying on hacked software and other machines to work.
Q: Does this card give me any other advantages for it's money.
A: To many to say:) You can fully control your UPS over network, turn on and off outlets, add temp sensors, add humidity sensors, using relays, logging, ...they are really to many.
Q: Why people even bother with this NUT ?
A: Because they are trying to make more basic model UPS's , who don't accept NMC cards to be able to shutdown multiple machines.
Q: Is is even possible to make NUT to work.
A: It is. Some people can cook an egg with very strong flash light , that don't mean it will as good as having kitchen.
Q: What would you do if if have few machines and 1 ups that don't support NMC Cards ?
A: I would pick one machine (as most important) and connect it directly to the UPS with USB or SERIAL , that's how I would be sure that at least this machine will properly shutdown independent from others.
Q:What you would advice me ?
A:If you really need a reliable solution, use the proper supported methods. After all the whole concept of using UPS is the reliability as main goal.
I hope this helps and answers a questions that were my own at some point in a early days of my research.
