The first step is figuring out what you want to use your data centre for. The roles of servers have metamorphosed since the 1990s, when commodity servers first started replacing peer to peer work groups in Windows 3.11 networks; what originally became a way to move files around grew into served applications (like web servers and email servers) and eventually grew into dedicated servers for applications like databases and code repositories, and networked storage solutions. Not that any of this was new - Unix servers had been doing this for decades, though Windows servers were (and still are) largely less capable of hosting multiple applications, though this is changing with the advent of virtualisation software.

Once you have determined what your data centre will be doing for your business, you have several other considerations to look into. Broadly broken down, these slot into overall cost to purchase, security, uptime and power consumption, and manpower requirements.

Cost to purchase is more than just the cost of the hardware; you will also need to buy equipment to keep the servers running - large cooling plant facilities and dry fire extinguisher systems. One of the places where costs can get daunting is setting up the first data centre; they are not cheap to set up and it's a trying decision to spend more money up front to save money down the road, while meeting the needs of the people using the data centre.

Related to cost is security; physical security ranges from the very low tech (installing it in an unmarked building, with berms and barbed wire) to high tech (palm readers that can positively identify someone by biometrics). Operational security includes tracking down the IP address, with Google Maps, of every person who tries to access the server to see where attempted accesses are coming from. Most people who use the internet have no idea how many attempts to break into servers there are each second. The short answer is that security costs a lot up front, and can cost more down the road…but this cost should be seen as an insurance premium against the price of losing your data or having it compromised. A final note - the more secure a system is, the more annoying it will be to use for your user base; don't buy security features you don't need; they will give a false sense of security and then be circumvented.

The highest expense of running a data centre, after the initial expense of the equipment, is energy costs. It's not just the energy costs of the computers themselves, but the energy costs of the support system (particularly climate control) that adds up over time. Nearly every major business with large data centres have moved to greater energy efficiency over the last two years, with the goal being to cut operating expenses or to keep them from rising. Avenues for this include sitting your centre near an electrical transformer station, using on site solar power during peak times and using passive air circulation units to pull in cold air from the outside rather than run the A/C on the server room in the winter.

The last place where data centres can be optimized is on manpower requirements; this is a fairly new field, and its benefits look quite promising, although implementations aren't living up to expectations - yet. The aim is to reduce the time needed to bring a server up and running by having a networked drive that has preconfigured installations designed to go on commodity server blades. When you increase capacity by adding a blade, you go to the network, tell it to image on the operating system and a package of applications, and tell its configuration file where to plug into the resources and it just scales up directly.

All of these tradeoffs make server room and data centre optimisation a challenge for any engineering and IT staff.