It was a long time coming but I've just had AC installed in my server room. I've also purchased a MiniGoose II from ITWatchDogs which I can't say enough about. So I'm covered by cooling, and I'll be alerted if something goes wrong but what if I'm a significant distance away? What I would really like to do is have a computer controlled winch which could be activated in the event of a problem. Can anyone suggest any hardware / software I might use for this? My MiniGoose II is capable of sending SNMP traps, emails and has consumable XML services so those could be the methods of sending / retrieving the alert. The server room has a security grate which is always locked off hours and a door which has no latch so if pulled would pop open. If our new AC system broke down it wouldn't take long before the temperature in that room hit 90. I was thinking about some sort of winch that could be activated somehow and would reel in its cable thereby opening the door.

Any ideas?

  • I think this would be more suited to our sister site superuser.com, if you don't mind I'll move it over there in 10 minutes or so. – Chopper3 Jul 22 '10 at 10:56
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    I'd disagree; this is a pretty common topic in the sysadmin world--environmental monitoring and what the hell to do when said monitor goes off, other than to panic. We're in an N+2 facility now, but many people aren't, and a good backup plan is worth its weight in (not-dead) servers, no matter where you are. – BMDan Jul 22 '10 at 11:03
  • I agree that the end result is sysadmin-oriented but ultimately the dude's asking about a computer controlled winch! I'm interested in the the solution but it's more likely to be answered by our SU colleagues. – Chopper3 Jul 22 '10 at 11:17
  • In the absence of heath-robinson.stackoverflow.com I think this should be closed. – Rob Moir Nov 19 '10 at 23:16
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    Have you considered building robots with articulated claws to open and shut the door? In off hours they can use video cameras to wander the hallways so you can justify the cost as both safety for the servers and for security of the facility. Maybe use web-cams to aim .22 caliber weapons? Instead of opening doors in an emergency they can just shoot holes in it and use fans build into the robot to force airflow out of the server room or annoy cornered burglars too. – Bart Silverstrim Nov 22 '10 at 14:12

Rather than a remote-control winch, I'd say what you need is simply a remote-control power strip (and, ideally, an IP camera to monitor things). Flip on the outlet for the winch, wait (x) seconds or watch the video to know when, and then flip it back off.

You could very easily script this into Nagios, and even include some elementary logic to try to guess whether the door is already open, but unless your server room has a ridiculous delta-T, paging someone to do it by hand is going to be a lot safer.

  • +1 for suggesting having a human do it – Oskar Duveborn Jul 22 '10 at 11:57
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    Our office only contains humans during a brief 8 hour period. I'm more interested in protecting our investment during the off hours. Using a remote control power-strip sounds like an interesting idea. Probably much cheaper as well. Thank you, I'll look into this. – JohnyD Jul 23 '10 at 11:32
  • Hire security to respond to temperature alerts outside of office hours? The cost compared to tinkering with spring-loaded doors could be about the same if you take time, testing and risk into account - but then again I don't know where this office is located so perhaps I'm completely wrong ^^ The suggestions involving less complicated and untested mechanics would get my vote if so, like the greenhouse hydraulics or an existing fire door lock system. – Oskar Duveborn Jul 26 '10 at 11:39

wouldnt it be easier to lightly spring load the door (to open, not close), and just use an electromagnet to hold it shut normally ? flip the magnet off and job done.

  • That's the way some fire doors are held open then released to close when the alarm is triggered. – Dennis Williamson Jul 22 '10 at 14:30
  • yes, this would essentially be that in reverse. – Sirex Jul 22 '10 at 14:40
  • That's a very good idea! If I went this route I wouldn't need to worry about power failure since a power failure would make the door open on it's own. I'll have this think about this some more. – JohnyD Jul 23 '10 at 11:41
  • Use a thermal switch (thermostatic switch) to power an electric door striker (latch). Buy one that triggers at say 85F, attatch it to your hot rack, and the door will pop open if the power fails, for the server room overheats. BTW this is a really cool idea. The strikers normally run on 24V, so it's a wall wart, some simple wiring, the thermal switch and the striker. Strikers come in fail closed and fail open. You want fail open. – Tim Williscroft Nov 20 '10 at 0:23

Technical gadgets in all their glory...

The usual solution I'd say is to wire a separate room temperature alarm to the burglar or perimeter alarm and give security the authority to open the door if deemed necessary.

Usually they can actually fix the problem on the spot as well, and they'll have a list of contacts to go through, not relying on you personally to be available, and a written set of instructions to follow. All security systems have temperature sensor options and this needs to be tested periodically (what you test is the actual incident response, not just the alarm system itself).

This makes me sleep well at night. A mechanical arm depending on a series of self-setup monitoring software and hardware, not so much. That would be an interesting secondary addition. If security calls you or someone else in the middle of the night and says they got a temperature alarm, it's always nice being able to confirm this through your own monitoring system - but it should always be separate from the actual room sensor imho.

Also, a backup and/or redundant AC is pretty common even in small one-rack server rooms due to their low cost compared to the alternatives, and a third cooling system from the building itself to help slow down the heat build-up if available.


I would be concerned about the safety issues of such a Rube Goldberg setup. I'd recommend a through-the-wall exhaust fan with louvers that close by their own weight and open with the force of the air blown through them. These can be thermostatically controlled.

Also, your winch, my fan and other possible technological solutions will fail for the same reason that the air conditioning failed if the power goes out. Which reminds me, there are louvers that will open without power based on a set temperature. They use a wax-filled "hydraulic" cylinder. The wax expands and opens the louvers when the temperature rises. They are commonly used in greenhouses. If (since!) your systems are on UPSes they will continue to produce heat. At least this passive system would let the heat escape (the louvers would be mounted high on the wall).

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    These things usually prove to be one's finest hour. There's a fairly famous computer operated lightswitch that uses a CD tray ejecting to flip the switch. – Tom O'Connor Jul 22 '10 at 11:05
  • You'd still need some way to turn on the exhaust fan, though. – BMDan Jul 22 '10 at 11:08
  • A light switch doesn't seem to be something that would decide whether the server room melts or not though? ^^ – Oskar Duveborn Jul 22 '10 at 12:04
  • @BMDan: These fans are available with thermostats, which I forgot to mention. @Tom: I almost linked to a story about that. – Dennis Williamson Jul 22 '10 at 14:29
  • Thanks for the suggestion. Unfortunately we aren't able to cut a hole in the wall to the outside. All the servers are connected through UPS so they will run for up to an hour in the event of a power failure. In 20 minutes without AC (and the door closed) the temperature goes from 68 to 88 degrees (my own tests). Since I have a security grate and a door it would be fantastic to just 'pop' the door open. The room would then stay at a manageable 80-85 degrees. The winch could be hooked up to a UPS as well. I use those cylinders in MY greenhouse! :) – JohnyD Jul 23 '10 at 11:40

Try to think about this morally and ignore the temptation to create an amazing hack. I know the question is to find a way to make a winch work but there's also a higher issue at stake here.

If your system is over-heating then you've a far greater risk of fire and some sort of automatic door-opening machine is a terrible idea. Failure of your thermal protection (ie, aircon) is a "shut the server down now" issue. If that server cannot go down, then implement some sort of redundancy but the problem lies with your ability to handle down-time not "how to stop the server exploding".


I can't help but laugh about the whole image of a winch pulling a door open. I've been in hundreds of data centers around the world and have never seen a setup describe such as this.

The standard practice is to shut your servers off to protect them but, honestly, it should never come to that if this is engineered correctly.

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