Data Center Racks

A separate cooling device probably isn't necessary if air flow in the room is decent. But if you have 43U of hot-running equipment--your rack is filled with blade servers and SAN switches--look for latch-on cooling systems. Liebert's add-on, Extreme Density, is designed for its enterprise-class racks.

These cooling systems tend to be liquid-based. Some use tap water, while others use chemicals that require less pressure. Most products also support simple fan-in-ceiling cooling add-ons. Determine your equipment needs, then ask your vendors what they recommend for cooling. Some vendors have calculated the "optimal" amount of airspace in the front door, some offer side-to-side cooling attachments to cover Cisco switches, some have extra fan arrangements, and, of course, some have liquid-based cooling systems.

If you need multiple racks, consider buying an extra cooling unit or a more advanced cooling system. APC, Dell and Liebert offer systems designed for larger setups and include modules that will help cool multiple racks in a non-data-center environment.

Got Power?

With regard to UPSs, you want enough redundant power to give you sufficient time to reach the room--physically or by way of remote administration tools--to power-down each piece of equipment gracefully during an outage. Allow a minimum of 15 minutes (per rack) to accomplish this.

Many UPS configurations are available. Some contain user-serviceable batteries; others require vendor-support engineers to fix battery problems. If the mini-data center you're building is at a remote location with no IT staff, consider a UPS that requires vendor-support engineers to come on site. Also, if you're negotiating a maintenance contract with your data-center vendor, be sure to include replacement of damaged batteries.

Next, determine how much power you're going to pull during normal operations. Remember, you're not in the data center anymore, so you can't pull more power over to a rack that's overutilized. You must ensure the room has the correct type of input power for the rack you're purchasing--some require 220 volts, which isn't likely to be available in a conference room, while others require three-phase to get the full output quoted.

Also, calculate the power drain of each piece of equipment to come up with a ballpark figure of your overall rack power requirements. If you're new to purchasing racks, rely on your vendors' and peers' experience to help design your system. Power and thermal needs combined will cause you problems in a blade-server environment, so expect to fill only about half a rack with these products. Check out vendor Web sites to find power requirements for their servers, switches and routers.

If you don't want to buy your rack and UPS from the same vendor, consider SharkRack's offerings. SharkRack sells racks but not UPS systems, so you can choose a UPS from any vendor.Remote management and monitoring are critical when your rack isn't in a typical data center. Nearly every rack vendor offers software to do remote monitoring and management--down to the "power cycle this plug" level--but test the software, or at least a demo of it, before you buy. You're going to be living with this software longer than most data-center applications stay in place.

Furthermore, check out the warranty and make certain you're getting sufficient coverage. We generally purchase racks on a 15-year cycle, betting there's not much that will go wrong with them, but it's always good to know you're covered.

All-in-One Units

Some vendors offer completely self-contained units, like those we mentioned from APC and Liebert. If you're building a data center outright and don't want to pay the hefty costs of remodeling office space to add more data-center floor space, these vendors will sell multiple racks for which you supply water and power, and the unit is otherwise self-contained, configured with hot and cold aisles, rack-wide cooling, UPS, power control and monitoring.

For the more extreme scenario of disaster recovery, APC offers a data center in a semi truck. The trailer takes one or two leads from the power company and offers 500U of rack space, an operations center, UPS and even satellite uplink if you need it (normal operations presumably would be to park it outside one of your facilities and connect directly to your network backbone). This might be a good option if your disaster-recovery plans include being able to move your data center to a safe place, no matter how widespread the disaster.Racks that offer data-center-quality space in non-data-center environments are becoming more technologically advanced each year. If you're thinking of remodeling entire sections of your building to increase data-center floor space, it'd be wise to give your rack vendor a call before you call the remodeling company.

Don MacVittie is a senior technology editor at Network Computing. Previously he worked at WPS Resources as an application engineer. Write to him at [email protected].