Preserving Our Land for Future Generations

Conservation Journal

Subscribe to Conservation Journal: eMailAlertsEmail Alerts newslettersWeekly Newsletters
Get Conservation Journal: homepageHomepage mobileMobile rssRSS facebookFacebook twitterTwitter linkedinLinkedIn


Conservation Journal Authors: Scott Allen, William Schmarzo

Related Topics: CEOs in Technology, VMware Journal, Infrastructure 2.0 Journal, IBM Journal, Conservation Journal, CIO/CTO Update

Blog Feed Post

Pros and Cons of Powering Down Servers

It seems like the most simple logical solution to energy conservation-powering down servers not in use

Infrastructure 2.0 Journal on Ulitzer

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.

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 IEits “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

Read the original blog entry...

More Stories By Lavenya Dilip

Lavenya Dilip was responsible for Marketing at Green Rack Systems.