As reliable as hard drives have become, they still have a finite lifespan. While regular backups and RAID technology can help you prevent data loss when a hard disk drive fails, it's better to catch the problem early and replace the hard disk drive on your schedule, rather than when it decides to fail.
Ironically, improvements in hard drive technology have caused some of the symptoms of impending failure to disappear. For instance, hard disk drive and controller designs now can hide the intermittent read/write failures that once foretold a hard disk drive going bad. Likewise, today's hard disk drives are virtually silent, which eliminates the changes in sound that used to alert IT personnel that a drive was going. Bearing failures, which used to be one of the most common causes of drive failure, are much less common today.
However, hard disk drives can still give off signs that they are about to fail. Including:
- Drive LEDs that never go off. There's no relationship between overt computer activity
and hard disk drive activity, as indicated by the drive LED. But if the LED used to come on
intermittently and now glows constantly, something is very wrong and is probably going to get
- Disk takes a long time to come up. A hard disk drive that takes a long time to boot up is working hard. Maybe it's working hard because a lot of stuff needs to be initialized. But it could also
- be trying to compensate for intermittent read/write failures.
- Disk cannot locate file table. If the disk can't find the Windows Master File Table
(MFT), especially after an unexplained crash, the disk is almost certainly dying.
- CHKDSK shows bad sectors. Bad sectors used to be a fact of life. Not any more. These
days, any bad sectors showing up with chkdsk or similar disk test utilities usually mean the disk
is going away. This is doubly true if the number of bad sectors is increasing, even very slowly.
- Running hot. All drives get warm, but if the hard disk drive itself is running unusually
hot compared to others in the enclosure, it is probably nearly the end of its useful life.
- Consider the drive's history. A hard disk drive that has been dropped onto a hard surface (running or not) or else has overheated should be regarded with suspicion. It's a good candidate for failure. Overheating usually occurs when an enclosure's main fan or fans fail, allowing temperature to build up. If the system gets hot enough that you start getting read-write errors before the problem is spotted and fixed, there's a good chance the lifespan of the drives has been drastically shortened.
About the author:
Rick Cook specializes in writing about issues related to storage and storage management.
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This was first published in July 2006