Five steps to more energy-efficient storage

Anyone who is responsible for managing a data centre understands the importance of efficient power. This is especially the case in data centres where consolidation and higher-density equipment have packed more and more devices into less floor space.

Although many companies have already consolidated their storage and server environments, they could benefit further by consolidating their storage-area network (SAN) environments. In fact, some data centres have reached or are nearing the maximum power allotment for their facilities, meaning there is simply no choice but to consolidate and deploy more power-efficient devices.

IT managers already know that servers are putting a strain on the world’s power grids, but what is often overlooked is the energy consumption of storage environments, which are expanding rapidly to accommodate the explosive growth of digital data. IDC calculates that 161 billion gigabytes of digital data was generated in 2006 alone.

According to Gartner, servers account for 40% of the data center’s power consumption, but storage comes in a close second, with 37 per cent. What’s more, storage-related devices — including SAN devices — can consume 1,000 watts or more. The lesson? When attempting to contain your data centre power usage (and costs), you can’t afford to neglect your storage or SAN environments.

What can you do to improve data centre power consumption? To better understand some of the issues, it helps to consider the analogy of transportation and fuel efficiency. Vehicles such as electric, hybrid or compact cars are obviously more fuel-efficient than larger, petroleum-fueled vehicles.

However, a larger vehicle such as a bus can provide a highly efficient mode of transportation since it can accommodate many passengers at a low fuel-per-passenger ratio. This concept reflects what is occurring in today’s data centres: consolidation of multiple devices into a larger shared resource. And if the shared resource happens to be a newer energy-efficient model, the benefits are magnified.

Continuing this analogy, here are five practical steps you can take to improve storage power efficiency in your data centre:

1. Consolidate, consolidate, consolidate. A bus uses more fuel than a car, but its per-passenger consumption is lower compared to individual cars. If you haven’t yet consolidated your SAN infrastructure, you might want to consider implementing a cost-effective yet scalable SAN director rather than continuing to add individual switches, which can consume more power in certain configurations.

2. Use the most efficient building blocks possible. Hybrid vehicles are more efficient than older gas or diesel-only models. Likewise, you can deploy the most modern, energy-efficient server, storage, and switch models to save power and money.

3. Power on devices only when you need them. Unplug any unused devices, which in the SAN include Small Form-factor Pluggable (SFP) devices. In the bus analogy, these devices would take up a passenger seat even if no one is sitting there, an inefficient approach to energy usage. Fortunately, many newer storage arrays will spin down their drives when they are not used (not yet provisioned) to save power.

4. Don’t neglect cooling efficiency. Equipment that runs hot or requires additional cooling considerations can significantly impact power consumption, and your budget. The more efficient your infrastructure, the less you spend operating your HVAC systems. Anytime your HVAC system has to work harder (think of a bus always driving uphill), your energy consumption and costs will be higher. Devices in the data center that enable you to implement hot-aisle/cool-aisle designs tend to be more efficient, whereas devices that don’t conform to a standard approach make the HVAC system work that much harder.

5. Work with vendors that participate in “The Green Grid.” The first industry initiative dedicated to advancing energy efficiency in data centres and business computing ecosystems, the Green Grid includes vendors who focus on solving the real-world data centre issues you face on a daily basis. The organization is chartered to develop platform-neutral standards, measurement methods, processes, and technologies to reduce overall power consumption in data centres around the globe.

By following these steps, you can implement an energy-efficient data centre that meets your particular business requirements. However, going green is more than just a way to reduce power usage or comply with a corporate mandate, it can be a smart financial move and strategic competitive advantage.

Crain is CTO of Brocade. Reach him at