Posted by: Matt Stansberry
Green data center
I just spotted a press release on a series of new analyst reports from Gartner on Green IT. Gartner says users should focus investments on areas that will provide the most bang for the buck. Unfortunately, their recommendations are vague. Gartner suggests pursuing tactics like “Changing people’s behaviors” and “Modern data center facilities design concepts”.
Does your CIO actually have undefined directives like this up on a whiteboard? Are your execs researching carbon offsets and investing in videoconferencing infrastructure for remote workers instead of dealing directly with the data center? The answer is probably yes.
There is still a huge disconnect between facilities and IT. In a recent SearchDataCenter.com survey, one-third of respondents said they didn’t even know how their 2008 power bills compared with their 2007 power bills.
Here is a green data center roadmap based on expert interviews and advice from SearchDataCenter.com.
Step 1, Get a mandate from the C-level execs: Chances are, your execs are talking about going green but have no idea how huge the data center’s energy footprint is. Put together a 60-second presentation on who pays the data center electric bill. What does it cost to keep the servers running per month? What are the cost trends for data center power over the past 24 months? How much additional capacity do you expect to need in the coming period? And how much would data center expansion cost? Don’t talk about kWh. Instead, explain that you are spending x-amount of dollars to provide this service today, and you think you can reduce the dollars you spend and provide the same level of service.
Step 2, Get started with PUE or whatever metric you like: Set up a simple metric like Power Usage Effectiveness to get a baseline of how much power is going to the servers and how much is being lost on cooling and infrastructure. Set goals to improve the ratio. Measure it in the same way consistently, over time. Keep an eye on ASHRAE for more specifics on green metrics best practices.
Step 3, Get rid of your dead and dying servers: The Uptime Institute estimated about a third of the servers in your data center are dead weight. Audit your hardware, decommission the non-functional machines and get them off the grid. Too often, companies pull servers out of production, only to put them somewhere else (test and development sandboxes) or worse, leave them up and running where they are. Decommissioned servers get lost in the shuffle. So how to you get rid of them? It takes brute force:
- Round up the legacy servers in your data center figure out what they are supposed to be doing.
- For the unknowns, take them through all the lines of business and ask “Whose servers are these?”
- If you end up with 30 orphans, you give it 90 days and pull the plug. If nobody screams, they’re not being used.
- If someone does scream, they needed the application, they don’t need the server. You’ve already shut that five year-old boat anchor off — port the application over to a more energy efficient Sun T2000 or new Dell server and speed up the whole thing.
As a next step, look to virtualize and consolidate workloads, turn on power-saving features and buy energy efficient hardware whenever possible.
Step 4, tune up that hot-cold aisle configuration: Over the past several years hot-cold aisle has became the de facto data center standard. But as server density has increased, efficiency gains have eroded. Hot aisle/cold aisle looks neat in drawings, but in practice, up to 40% of the air doesn’t do any work. Hot air goes over the tops of racks and around the rows, or up through holes in the floor where it isn’t needed. Data center pros can make huge gains by sealing up the floor and right-sizing the CRAC units to the new configuration.
- Eighteen inches is the minimum recommended raised floor height — 24-30 inches is better, but not realistic for buildings without high ceilings.
- Keep it clean! Get rid of the clutter under your raised floor, like unused cables or pipes. Hire a service to clean it periodically. Dust and debris can impede airflow.
- Seal off cable cutouts under cabinets, spaces between floor tiles and the walls, or between poorly aligned floor tiles. Replace missing tiles or superfluous perforated tiles.
- Use a raised floor system with rubber gaskets under each tile, which allows tiles to fit more snugly onto the frame, minimizing air leakage.
- There are several products on the market to help data center pros seal up raised floors, including brush grommets, specialized caulking and other widgets.
For more info on blocking holes in your raised floor, check out Bob McFarlane’s tip on SearchDataCenter.com.
Taking this a step further, some data centers are containing the hot and cold aisles with plastic sheeting and plenum systems and achieving huge energy savings. When making these adjustments, data center managers need to carefully check how changes to their systems are affecting temperatures and energy usage across the data center. Check out this review of CFD analysis for more info on the tools for this job.
None of these suggestions are revolutionary, high-tech or even particularly confusing. The best advice for IT execs struggling with “Green IT” is to take a true accounting of the energy costs in the data center, and then sit down with the facility engineers and IT teams in the same room and hash out a roadmap.