Green Notes

IBM, Syracuse University (SU), and New York State have built a computer data center on the university’s campus that  incorporates advanced infrastructure and smarter computing technologies to make it one of the most energy-efficient data centers in the world. The data center is expected to use 50% less energy than a typical data center today making it one of the greenest computer centers in operation.

A key element of the design is an on-site electrical co-generation system that uses natural gas-fueled microturbine engines to generate all the electricity for the center and provide cooling for the computer servers. SU will manage and analyze the performance of the center, as well as research and develop new data center energy efficiency analysis and modeling tools. The data center operates completely off-grid.

In addition, a liquid cooling system has been created that will use double-effect absorption chillers to convert the exhaust heat from the microturbines into chilled water to cool the data center’s servers, with sufficient excess cooling to handle the needs of an adjacent building. Server racks  incorporate IBM’s Rear Door Heat eXchanger “cooling doors” that use chilled water to remove heat from each rack far more efficiently than conventional room-chilling methods. Sensors  monitor server temperatures and usage to tailor the amount of cooling delivered by each Rear Door Heat eXchanger–further improving efficiency.

The project includes the creation of a direct current (DC) power distribution system. In a typical data center, alternating current (AC) electricity is delivered by a central power plant through the local utility’s electric grid and then converted to DC to power the servers. This conversion process results in power loss. By directly generating DC power on-site, transmission and conversion losses are eliminated.

What makes the IBM-Syracuse University project different from many other similar ventures is the fact that special attention has been paid to greening the actual infrastructure of the data center itself, not just the computer hardware and software. Other design solutions that we recommend at Green Rack Solutions to update your data center’s basic design are:

• Managed airflow system to avoid hot spots, to assess cooling capacity required for IT equipment and to separate cool intake air from warm server exhaust air.
• Using energy saving cooling methods such as airside economizers and direct evaporative cooling.
• Larger but fewer variable speed motors to power air handlers for energy saving.
• Data center designs that eliminate need for raised floor which creates additional losses and leakages in the air handling system, thereby reducing the efficiency of the overall cooling systems.
• Designing by density zones. High-density applications represent 10 percent to 15 percent of a total data center usage. Medium-density apps account for another 20 percent. The rest is low-density. If you mix and match densities you save money on the build-out.

It seems like the most simple logical solution to energy conservation-powering down servers not in use. After all not all servers are used all the time. For example servers that perform only a single predictable function such as for calculating the employee pay are used only on certain days in a month. Or those used for special testing or running backups and so on. It makes sense that they power themselves down when not in use just like in commonplace electronic gadgets.

The Alliance to Save Energy, Kelton Research and 1E, a software IT company, found through surveys of server managers and analysis of industry data that out of the world’s 44 million servers, roughly 4.7 million of them are idle and not doing necessary work.

“Contrary to popular belief, one of the largest causes of energy and IT operational waste in data centers are servers that are simply not being used. The savings from decommissioning non-productive servers cannot be ignored. Organisations need better information on server efficiency and more effective ongoing server energy management,” comments Sumir Karayi, CEO, 1E.

The key problem highlighted in the study is that over eight in ten (83%) of IT managers admit that they do not have an adequate grasp of server utilization . That is they have no idea which of the servers are actually in use and which are not at a given point of time. So to be on the safe side and avoid any unwanted interruptions while running applications, they supply power to all servers uniformly even those that are not working.

But not all IT managers approve of powering down servers. The old school of thought seems to be that servers should run 24/7 for fear of ruining the hardware and also of getting a bad rap sheet from clients. Others dread the difficulty of getting a server back to an operational state once it’s turned back on after powering down.

Ted Samson in infoworld interviewed several experts on this issue:

Infrastructure technologist at HP, said powering down servers is completely safe. “It’s not at all bad for the server. It’s something we do to electronic devices all the time. It can handle it from a hardware perspective,” said Baker.

But Brad McCredie, an IBM fellow for the Systems and Technology Group, wasn’t quite so sanguine. He explained that, technically speaking, powering off and on any kind of computer can have a detrimental effect over time.

“[Temperature cycling] is a well-established failure mechanism and a stress on components,” McCredie pointed out. “What it really comes down to is all these things — chips soldered on modules, soldered on boards and connectors — that expand and contract when they heat and cool…. When they all contract and expand at different rates, they can fail. That’s ultimately the bad thing with power cycling,” he said.

Mark Monroe, director of sustainable computing at Sun, suggested that machines can handle being shut down a finite number of times. Arguably, the number is large enough for regular power cycling over an extended period of time. “Most server vendors today say they’ll support a certain number of cycles of powering things on and off,” Monroe said. “I believe most of the server vendors would say [the number] is in the hundreds as opposed to the thousands.”

From the above survey it is safe to assume that for the most part , datacenters armed with the burden of reducing power costs are willing to at least take a look at this controversial method in moderation.

There have been a host of products in the market recently to tackle efficient power downs without mess-ups. IE launched its power management software for servers that use smart algorithms to figure out which servers are doing work and the energy they are using. According to IE its “NightWatchman Server Edition” can power down servers into a drowsy state, cutting their energy use by 12 percent. IBM has a product called Active Energy Manager that features advanced energy control options designed to boost performance per watt by slowing processor clock speed or even putting processors in “nap” mode when not in use. There are numerous others following the same trend including VMware that offers a functionality in VMware Infrastructure 3.5 called Distributed Power Management that powers servers on and off according to demand level.

Not all servers are automatic candidates for shutdowns however. Servers dedicated to specific scheduled computing that occurs only at certain times of the month or wanes at certain pinpointed times during the day are ideal targets for powering down. For more expert consultation on powering down processes and other methods of energy saves for your data center, contact us at GreenRack Sysems/408-2138144.