Slashdot Mirror

http://www.apcupsd.com/

Apcupsd can be used for power mangement and controlling most of APC's UPS models on Unix and Windows machines. Apcupsd works with most of APC's Smart-UPS models as well as most simple signalling models such a Back-UPS, and BackUPS-Office. During a power failure, apcupsd will inform the users about the power failure and that a shutdown may occur. If power is not restored, a system shutdown will follow when the battery is exhausted, a timeout (seconds) expires, or runtime expires based on internal APC calculations determined by power consumption rates. Apcupsd is licensed under the GPL version 2.

The developers system
http://matou.sibbald.com/cgi-bin/multimon.cgi

First, do the math. Calculate the run-time power consumption of your servers. The easiest way is to use real numbers from the existing UPS units, or by using a kill-a-watt.

Second, buy APC UPS units to meet your need. UPSes are rated for the number of actual watt-hours they support. If your servers consume 1500 watts, and you need them to operate for 30 minutes on battery, you'll need at least 750 watt-hours. Considering adding 50% for battery deterioration, and future expansion.

No, I don't work for APC, but they have worked exceedingly well for me and they are supported on practically any operating system you run.

In my network, we have a Linux machine monitor the UPS via USB serial cable using apcupsd, which you can find in your distro's repository. Then all the other machines are linked to that machine also using apcupsd but with an ethernet target instead of USB. When the UPS fails, the others find out within 20 seconds (or whatever your poll time is), and take action. Any data the USB host has, the others have from the network. It is easy to fetch the data via SNMP, graph it in Cacti, etc.

Why does each server has its own UPS? Use a single UPS with more power. To notify all machines about a power outage or a low battery state, use either a special distribution box from the UPS manufacturer, or make one server the "UPS master" and let it notify the other servers via ethernet. (Connect the ethernet switch to the UPS.) Have a look at http://www.apcupsd.com/ for a free (as in speak and as in beer) solution that works not only with APC UPSes.

Why do you need three servers? One more powerful machine and some virtualisation software could emulate the three servers. Such software is available for free (as in beer). That would also solve the UPS notification problem, because only the host OS has to be notified.

Think about alternative doors. There are doors that can be folded instead of swinging into the room, like this one: http://www.marley.de/produkte/falttueren/rapid/ind ex.htm

Separate servers and user(s). You simply cannot work in a room where at least three servers and a UPS generate noise and heat. And the machines can't, either. You need an air conditioning system to cool down the machines, so you get even more noise. Put the servers into a separate room, perhaps a broom closet or into the basement. At least, use some wood and a folding door to separate a small part of the room from the rest for the servers, that's what I did in my home office. Folding doors aren't the perfect noise guard, but they attenuate the noise a little bit, especially the high frequencies.

Think about housing the three servers at some hosting provider, that gives you a reliable power supply without your own UPSes and air conditioning for the servers. Use a high-bandwith connection and VPN and you do not need more room than a single ethernet socket for any amount of servers.

Tux2000

I second that. You can have Smart Run a script when things fails, like Mailing the details of the failiure and then turning off the computer.

For other computer parts lsensor might do the trick.
For exemple: http://gentoo-wiki.com/HOWTO_Monitor_your_hard_dis k(s)_with_smartmontools

if it's an external device, the best thing would be to get a controlable UPS And turn off (again with a small script)

Just think RAID, UPS, smart monitors and deamons and with a bit of imagination, you can come up with a soultion.

Anyone who has done this design knows that there is more cost in what happens on the whiteboard than something like this at the component level.

Right. The 8-bit chips have fewer pins to tie down, so there's less that can go wrong. There are fewer registers, a simpler assembler language (for the 5% of the coding that takes 50% of the time :-), and everything is well-known.

But there are applications for a 32-bit computer on a chip. Want an IP-addressible toaster with built-in clock synced to NIST? IP stacks work better with 32 bits. Add a serial port, and your toaster alarm could control your UPS.

Anything where there's already a high level of complexity in the application can benefit from something like this.

As for apcupsd, it works very well. I have a Back-UPS ES 500VA hooked up to a Linux server via the USB cable, and it works very well. I've tested it and watched it compensate for real world outages, as well as observe it doing regular tests. For your ease of reference: Apcupsd's Support for USB UPSes.