On Jan 14, 2014, at 2:06 PM, Hugo Mills <h...@carfax.org.uk> wrote: > On Wed, Jan 15, 2014 at 03:00:21AM +0600, Roman Mamedov wrote: >> That said, do not fall into a false sense of security relying on proprietary, >> barely if ever updated after the device has been shipped, and often very >> peculiar-behaving SMART routines inside the black-box HDD firmware as your >> most important data safeguard. >> >> Of course SMART must be checked and monitored, but don't delude yourself into >> thinking it will always warn you of anything going wrong well in advance of >> failure, or even at all. > > The famous paper from Google a few years back suggested that SMART > was a useful predictor of failure in something like 20% of failures.
https://static.googleusercontent.com/media/research.google.com/en/us/archive/disk_failures.pdf "Out of all failed drives, over 56% of them have no count in any of the four strong SMART signals," and "even when we add all remaining SMART parameters (except temperature) we still find that over 36% of all failed drives had zero counts on all variables." For those that do report counts, they still weren't able to come up with a good predictor of failures based on any combination of the current attributes. So there's a really good chance the drive will fail without warning. This study doesn't report on the accuracy of the health self-assessment, i.e. the PASS/FAIL state for the drive. Chris Murphy-- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
