Welcome to the first edition of The Hot Aisle.
Going forward I will attempt to tackle, or at least provide some insight into, the current practices (good and bad), trends and future developments in the infrastructure of the data center.
Of course, the term "data center" means different things to different people. To some, a "real" data center is at least 1 megawatt and 10,000 sq ft. or larger. To others it could be the first real dedicated space in the office, so they could finally get the servers off the shelves and out of the "server closet" -- and perhaps even install them in racks, with some form of "dedicated" cooling, even if it is only a window air conditioner.
In reality, the care and feeding of IT equipment is a highly varied challenge that has been addressed in many ways, some extremely well designed while others are somewhat marginal. In some cases, it depends on the size and type of the organization, but in numerous cases it is determined by how, or if, upper management perceives the importance of IT as a valuable resource, not just as another operational expense. Of course in all cases, upper management always expects that all IT resources are available 24/7, regardless of the budget and resources they allocated to maintaining the data center. We all want to have to the reliability of a fully redundant Tier IV facility, but may only have the budget to barely operate on a Tier 1 level.
Even the term "State of the Art" data center means different thing to different people. Until just recently, the traditional mantra has been the proverbial "5 Nines" of reliability as the primary chant. Moreover, while power densities were moving upward, many new sites that were built only 3 or 4 years ago cannot support more than 100-150 watt per square foot, since they were originally designed back in 2002-3 when that power level was seen as "the future." In the interim, the price of energy rose significantly and power generation and transmission systems have become capacity-constrained, and suddenly the words "green" and "energy efficiency" were added to the data center lexicon. And thanks to "the Green Grid," we are all now supposedly striving to lower our PUE, as well as our cholesterol.
Even ASHRAE, the stalwart of data center standards, recently revised the golden rule of 68-72�F to allow up to 80�F in the Cold Aisle (per 9.9 - the "inlet air temperature of the IT equipment") as part of the re-evaluation to improve energy efficiency in the mission-critical space. Of course, if this paradigm begins to take hold, it will bring new meaning to the term "Hot Aisle," as the exhaust air of the servers begin to exceed 100�F.
As 2009 draws to a close, we are now entering the second decade of the new millennium and the density levels that are being discussed for some of the newest water-cooled systems are targeting 50 KW per rack and higher. Moreover, after many years the US EPA, which had previously exempted servers from the Energy Star Program, has finally issued the first standard covering servers in May 2009 (see Energy Star for Servers ver. 1.0), yet it still exempts blade servers, which represents today's mainstay of the virtualization push toward computing efficiency.
While industrial production in the U.S. continues to decline, data centers have become "data factories" and are being treated that way from the government's point of view. The U.S. Dept. of Energy Industrial Technologies Program (ITP of the US DOE-EERE for data centers) is working with the data center community to reduce energy consumption 10 percent by 2011. It just released the Air Management Tool ver. 1.05, to help improve cooling efficiency. Yet new multi-megawatt data centers, some the size of 10 football fields, are being built at an unprecedented rate. (I wonder how many megawatts hours have been expended to ensure that everyone can see a dancing cat on YouTube).
Clearly there are multiple factors in play that will affect the data center environment. I believe that this rising trend in power and cooling is not going to continue as an endlessly rising curve and would like to point readers to "Inflection Point - The Future of the Data Center."
So, in closing, order your pina coladas now, and join me for more updates and developments in future editions of The Hot Aisle.