On Wed, Apr 18, 2007 at 01:25:19PM -0400, Lennart Sorensen wrote: > > Does it matter that google's recent report on disk failures indicated > that SMART never predicted anything useful as far as they could tell? > Certainly none of my drive failures ever had SMART make any kind of > indication that anything was wrong.
I saw that talk, and that's not what I got out of it. They found that SMART error reports _did_ correlate with drive failure. See page 8 of: http://www.usenix.org/events/fast07/tech/full_papers/pinheiro/pinheiro.pdf (If you're not a USENIX member, you may be able to find a free download copy elsewhere.) However, they found that the correlation was not strong enough to make it economically feasible to replace disks reporting SMART failures, since something like 70% of disks were still working a year after the first failure report. Also, they found that some disks failed without any SMART error reports. Now, Google keeps multiple copies (3 in GoogleFS, last I heard) of data, so for them, "economically feasible" means something different than for my personal laptop hard drive. I have twice had my laptop hard drive start spitting SMART errors and then die within a week. It is economically quite sensible for me to replace my laptop drive once it has an error, since I don't carry around 3 laptops everywhere I go. -VAL - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/