ColoFAQ - the.earth's UK Tech wiki

Colocation Tips

Things you should be aware of if you're planning to colo a machine anywhere. I've seen all of these, usually several times.

Make sure it auto powers on

Most colo facilities these days provide a remote power cycler that enables you to power cycle your machine if it should fall over for some reason. This isn't much use if your machine decides to stay off when it loses power. Decent BIOSes have an option for something like "Off", "Last state" or "Always on". You want "always on". Really. Alternatively there's a paper clip hack you can do the ATX power connector to make sure it's always on, but you probably want a better mobo instead.

Make sure it boots to the OS without intervention

Even if you've successfully configured your machine to make use of the power cycler you need to ensure that it'll reboot cleanly into your chosen OS. Without a keyboard or monitor attached. Without needing to press any keys to get past the BIOS or anything.

Bring it properly configured

Ideally a colo install should consist of nothing more than putting your machine in the rack, attaching power and network cables and then ensuring you can get to it from another machine. This means configuring the network appropriately beforehand and making sure you haven't managed to firewall yourself out from accessing the machine.

Get a serial console

If your OS can support one, get a serial console. This gives you a method of getting into your machine if you manage to break networking somehow. It also provides a method of seeing any error messages that may have been output before a crash. And it provides reassurance that the only reason a reboot is taking so long is because you're fscking your 1TB disk array.

Cool it well

Modern CPUs kick out a lot of heat. The logistics of cooling them in a 1U case are reasonably different from cooling a large tower where you can fit lots of big fans easily. Likewise when you put 20+ (some providers fit 40+) machines in a rack then even if the colo facility is decently airconned your machine is going to be in a hotter environment than sitting on your floor/desk on its own. So it pays to over engineer your cooling. Or if you can get away with a lower powered CPU then that's worth considering - the Via Eden processors run pretty cool for example.