Many organizations are opting to move into a colocation facility rather than build out or expand their own data centers. Colocation enables them to preserve capital and move data center expenses to the operational side of the ledger.
But moving into a colo doesn’t eliminate the need for effective capacity planning. It’s critical to ensure that you’re maximizing the value of the space and power you’re buying from the colocation provider.
Colocation facilities sell power in fixed increments, often 5KW per rack. If you install gear in the rack that’s drawing only 2.5KW, you’re paying for power that you’re not using. That’s known as “stranded power.” If the rack isn’t full, you could put more equipment in it and use up more of the power. But if it’s full, and you need to move more gear into the colo, you’re going to have to add another rack. Now you’re paying for more space and another 5KW of power. As your environment grows, your colo bill becomes much larger than you had planned.
How does this happen? The reasons vary, of course, but it often has to do with underutilized equipment. Many organizations have servers that are operating well under capacity. Maybe there’s an application that runs only three hours a day, and the server sits more or less idle for the other 21 hours. In an on-premises data center that might not make too much difference. But in a colocation facility that server is taking up space in a rack and you’re paying for power the server isn’t using.
Managers of hyperscale data centers know at a granular level how much power each piece of equipment draws. But most IT professionals have only a basic understanding of power requirements. You might think it makes sense to look at the power specifications listed on the faceplates on the equipment and do a little bit of arithmetic. However, equipment manufacturers almost always overstate power requirements, so you’ll still end up provisioning more power than you need — particularly if that equipment is underutilized.
If you’re planning to move into a colocation facility, it pays to do your homework before you sign a multiyear contract. By setting up a testbed in your lab, you can monitor how much power the equipment consumes under actual workloads — both at the rack level and, ideally, at the device level. Monitoring power consumption at the device level is more challenging, but it will help you determine the best rack configuration for your colo deployment.
The same principles apply when deciding to expand your colo space. Before buying another power width from the colo provider, analyze your current utilization levels and determine if there are ways to optimize your existing rack space. Can a server support another virtual machine? Can you consolidate or remove devices from the rack? Again, monitoring power consumption at the device level will help you make more-informed decisions.
Rahi Systems has extensive, real-world experience in the design and optimization of data center infrastructure. We have an array of software and hardware tools that can analyze power consumption, providing our experts with granular data for configuring highly utilized, high-density racks. Let us help you plan your colocation capacity so you gain maximum value from your investments.