The Google study also found that no single parameter, or combination of parameters, produced by the SMART (Self-Monitoring Analysis and Reporting Technology) built into disk drives is actually a good predictor of drive failure.

The bottom line

For customers running anything smaller than the massive data centers operated by Google or a university data center, though, the results might make little difference in their day-to-day operations. For many customers, the price of replacement drives is built into their maintenance contracts, so their expected service life only becomes an issue when the equipment goes off warranty and the customer must decide whether to "try to eke out another year or two" before the drive fails, said Garrett.

The studies won't change how Tom Dugan, director of technical services at Recovery Networks, a Philadelphia-based business continuity services provider, protects his data. "If they told me it was 100,000 hours, I'd still protect it the same way. If they told me if was 5 million hours I'd still protect it the same way. I have to assume every drive could fail."