How Do You Evaluate a Data Center?

mpapet writes to ask about the ins and outs of datacenter evaluation. Beyond the simpler questions of physical access control, connectivity, and power redundancy/capacity and SLA review, what other questions are important to ask when evaluating a data center? What data centers have people been happy with? What horror stories have people lived through with those that didn't make the cut?

Comments

Re:Just off the top of my head

[JWSmythe]

    I noticed something when touring one datacenter. They had a neat conference room that overlooked the whole datacenter. You could see the heat rising off of one area (Google's room). They went on and on about the wonders of their cooling, and how they had so much capacity.

    We later took the guided tour. The person I was with was talking to our guide, and I was paying careful attention to our environment. There were tremendous hotspots on the floor. We're not talking about 78 degrees. It was closer to the 90's. Other spots were downright cold. Why? Because they had all this capacity, and no real planning. The circulation was insufficient, even though the capacity was available. A well populated rack will always be hot at the back, but it's expected that they will draw the air off of that area rather quickly. I've even seen datacenters that enforce their hot/cold aisles, but then there isn't much of a reason for it. There is no air return on the hot side, and it's just blowing at another aisle's cold side.

    Sometimes it's good to just walk the floor with a tech (not a salesman), and ask questions about the operation. What kind of fiber do you have coming in? How many providers? How good are your generators really? Do you test them on a regular basis? I've found a sales minion will say there are a dozen providers coming in, but it will turn out that only one has substantial fiber, and the others are sharing that. {sigh} Sometimes they will have generators, but they've never test fired them. Sometimes the tech is just frustrated at the nonsense at that datacenter, and that's indicative of how it's going to be to work with them.