Slay your zombie servers

Datacenters are plagued by underutilized hardware that do little more than jack up utility bills and take up valuable space

Deep within the bowels of your datacenter, unspeakable horrors -- the living dead! -- may dwell. Like zombies, these mindless minions feed greedily on, well, not brains, but electricity, a costly resource for a datacenter operator. They also take up precious space, something that many a datacenter operator can't afford to spare.

I'm talking about "zombie" servers, machines that, for whatever reason, have been left in the rack, powered on but doing very little or no work whatsoever. Now, if these were certain banking execs, they might receive huge annual bonuses for their non-efforts. But they're not, and it's in IT's best interests to weed out these near-dead machines as quickly as possible.

Some perspective as to how significant a problem zombie servers are: A study by McKinsey and Company titled "Revolutionizing Data Center Efficiency" found that among a total of 458 servers at four production datacenters, 32 percent (146 in all) were running at or below 3 percent utilization. Moreover, according to the same study, it can cost between $1,320 and $2,020 per year -- factoring in electricity, cooling, and other operational costs -- to support a single mid-tier ($2,500) server.

[ Learn more about what McKinsey discovered in its groundbreaking report. | Keep abreast of green IT news and trends by subscribing to InfoWorld's free Green Tech newsletter. ]

So then: Imagine you're running a 1,000-server datacenter and you discover that nearly one-third of your machines are superfluous. Well, you'd have a wealth of options. You could retire those machines and look at annual savings of, on the low end, $396,000 (that's 300 servers times $1,320). Or perhaps you could joyfully announce to the CXO that the expensive datacenter expansion project can now be put on hold because you've figured out a way to free up about a third of your datacenter space. (In this case, you might even get the bonus -- or it, too, might somehow end up in a banking exec's pocket.)

Unfortunately, though, hunting down and slaying zombie servers isn't particularly easy, especially in a large datacenter. Hardware vendors haven't designed machines yet to tap you on the shoulder and complain that they have nothing to do. But there are ways.

Among them, a company called Tideway offers a product called Foundation, an automated application mapping solution. It discovers all the hardware in your datacenter, from switches to servers, as well as what apps, OSes, and databases are running on them. On top of that, it maps all of the dependencies among them, including which servers are using which network connections and conversing with which databases.