Monday, November 20, 2006

Building a cheap datacenter

Eric and I are building a cheap datacenter for Trileet that we can reasonably say has at least 4 9's (99.99%) uptime. Cheap is a relative term of course, plenty of companies would feel perfectly good about doing that with a $15k budget, but we wanted to aim for something closer to $5k.

Achieving 4 9's is in theory fairly simple:
  1. Build software that doesn't break. Ok, that's not so simple, but doable, and that's something we are pretty good at. Without getting into the hows of accomplishing that, let's just say that's in the bag.
  2. Make sure you don't have a single point of failure.
  3. Configure everything to automatically reconfigure in case of failures.
#2 reminds me a lot of rock climbing techniques. Whenever climbing you pretty much always make sure that one thing going wrong won't kill you. IE, when you are climbing, you have someone belaying you, so that if you fall (one thing going wrong) you don't die. Or when setting up an anchor, you always make sure that no single piece failing will cause the whole thing to pull out and sending you to your death.

The same is true when building a data center. You need n+1 of everything, where n is the number you need to scale appropriately.

In our case, n is simply one. We aren't doing anything ridiculously expensive and servers are fast these days. So that means two servers.

After looking around a bit, we chose Dell 1950's. These seemed like a good balance between good performance, 1U of rack space and with enough headroom to upgrade if need be. Configured with an Intel 5130, 2 GB of ram and 160 GB of disk these should do fine for now.

Two of those brings us to about $3400, so that leaves $1600 for other things.

I'll cover what we spent the rest of our money on in upcoming posts, along with some pictures of our set up once complete.


Michael said...

Have you considered leasing hardware, or just going with external hosting providers like layeredtech, theplanet, rackspace, etc? Considering the extra amount of time & effort that you'll put into managing things like spares & connectivity, and the depreciation of hardware, it might not be a bad thing to utilize outside providers.

Nic Pottier said...

Ya, we've thought about it, but in the end I think it actually ends up being cheaper to build your own. Yes, there's a capitol expense up front for the hardware but the colocation itself is fairly cheap. (we are paying $150/month for 4U's of space with two 100mbps drops)

In our setup, we'll actually have three hosted boxes and have complete control of them.