DIY server cabinet
Ages ago, when we moved to London and had to downsize from a two-bed terraced house (a garden!) (our own personal stairs!) to a one-bed flat, I discovered that we had a problem.
For several years I'd been using an old PowerMac 7300 as a PPC Debian-based mail server. It lived in my office (the second bedroom), from back when I was a sole trader and worked from home. It wasn't as loud as an Xbox, but it was close. It didn't matter in the office, but when we moved to London and it had to live on the bookshelf in the lounge... Well, it started to matter.
The solution seemed obvious: a Mini-ITX based server which would be very quiet indeed. The components for said server were purchased and assembled. I was very pleased. Until I switched it on and discovered that the case fan, which was a 40mm fan, made a lot of noise. This was solved by putting a fan-speed controller in and ratcheting the speed down. The server lived in a few places (all ridiculous) and eventually it occurred to me: One of those cube-things from Habitat would make a great server cabinet for a little box like that.
The cube was bought, assembled and it sat around with stationery in for a while. The server was tried inside the cube, and it ran super hot. Really, like a furnace. So that was no good.
What was needed was airflow, which meant a hole. A big hole.
The Travla C158 case I've got pulls in air from the top and sides and exhausts through a hole on the bottom of the case, where the fan is located. With a cabinet you ideally want airflow front-to-back, pulling in cold air from one side and exhausting it out the other, without too much mixing going on.
After consulting my friend Fraser, who knows about such things, a plan was devised:
- Make a hole in the back of the cabinet
- Put a skirt around the front and sides of the case (avoiding the intake holes)
The result should be that the case pulls cold air from the front of the cabinet, through the case and out of the bottom. The skirt means that all that hot air flows towards the back of the case, and out of the hole in the back of the cabinet, giving the proper kind of airflow necessary for good cooling.
So, here's the cabinet:
Making a big hole meant routing, not drilling, so I needed a router (row-ter, power tool; not roo-ter, network device). I got a really cheap (30 quid) router from B&Q, made some measurements and marked up the back of the cabinet with pencil so I knew where to rout out.
The back of the cabinet was thin veneered plywood, so I covered the inside of the area to be routed with masking tape to try and prevent the router bit splintering the plywood's surface at the edges of the hole.
Then I started routing, which is actually quite tricky. It started to jump around a bit because I wasn't controlling it properly, and pretty soon all the nice neat lines I'd drawn had gone to pot...
Once I'd done, I was left with a dirty great hole in the back of the cabinet and, although it wasn't the neatest job in the world, it was a perfectly reasonable gaping hole.
You can see the remains of the neat-but-ignored pencil marks.
I then made a skirt for the server, it's very crude: just some bits of light card held together with sticky tape at the corners, and masking tape to hold it down and secure it to the server.
The size of the hole meant that when the server was put inside the cabinet it was dead easy to put the power and network wires through the hole, so there's no mess of cables at the front of the cabinet, which is good. Since the next photo was taken I've removed the network switch from inside the cabinet and put it on top (on top of a PC) because it was getting quite warm, and it was quite awkward to get to, but basically this is what it looks like in situ:
There was fan noise still, so I replaced the 40mm case fan with a quieter one, fitted it with vibration damping rubber fan mounts, and replaced the case feet with super-soft silicone rubber ones (all from Quiet PC). That helped with the noise, and seemed to eliminate the cabinet vibrations that were causing some of the more annoying noise.
The main lessons I've learned from this were:
- Routing is fun.
- The shelf in a Habitat Cube cabinet is a bit too much like a sounding board, thus making the cabinet a less than ideal choice, despite being attractive, and a decent size. You want something less springy.
- Mini-ITX cases seem, by and large, to be too small for their own good: 40mm case fan == hard-to-stop fan noise.
I think I've figured out the ideal solution, though. My Mini-ITX box uses an Epia PD 6000E, a 600 MHz fanless board. It performs very well: 600 MHz is plenty of horsepower for a mail server and DNS cache. So, I don't need much power, and I need the box to be small and quiet. I'm thinking that the Core Solo Mac Mini would fit the bill perfectly, given that it'll happily run Linux, is tiny, and nearly silent (by all accounts). Grrrr. Still, it was fun building it...
You can see the rest of the DIY server cabinet photo set at Flickr, if you're really bored or something.
- 10.6.2006, 13.50
- File under: DIY, woodwork, routing, power tools, IT infrastructure, server cabinet, bad idea