Powering Down Drives Is a Sticky Problem

Users who took the advice of Y2K doomsayers and powered down disk drives that usually run nonstop could regret doing so. The drives could fail on power-up due to a condition called "stiction," which has nothing to do with the Y2K rollover.

Ask multiple experts to define stiction, and you'll get multiple answers. But they'll offer one solution: Keep long-running drives running, and replace drives that are at least 6 years old.

Some experts say stiction is caused by "grunge" accumulating on the drive head.

Periodic power-downs clean off the grunge, which is why long-running drives are susceptible to stiction.

Other sources say coagulated lubricant sealed in the drive spindle prevents the drive from turning at power-on.

An advisory published by the SANS Institute in Bethesda, Md., warned of grunge-based stiction among drives that have been running for months prior to being shut down for Y2K.

The author of the advisory, Greg Houlette, recommended parking the drive heads without cutting power to the drive, a technique known as "spinning down."

Charles Burns, an analyst at Giga Information Group Inc. in Cambridge, Mass., said the most stressful part of an electronic device's life is when it is turned on. Thus, spinning down, rather than powering off, is a good solution.

SANS director Allan Paller said that six years ago a major IT vendor lost 18 disk drives to stiction. But Paller said that, to his knowledge, no stiction problems occurred as a result of the year 2000 rollover.

Rather than powering down for the year 2000 rollover, Dalton, Ga.-based Shaw Industries Inc. backed up data through about 10 p.m. on Dec. 31 and suspended transaction processing on its Groupe Bull mainframe until after midnight, said IT director Robert Watson. Six months ago, the company took the added precaution of buying new EMC Corp. drives because it didn't want to roll into the year 2000 with old hardware, he said.

Marc DeNarie, an operations supervisor at Pacific Gas & Electric Co. in San Francisco, said that the company's now-retired Control Data Corp. mainframe system had exhibited stiction in the past and that the company has stopped powering down drives as a result.

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