On Tuesday 04 January 2005 20:57, Mikael Abrahamsson wrote: > On Tue, 4 Jan 2005, Maarten wrote: > > failures within the first 10 years, let alone 20, to even remotely > > support that outrageous MTBF claim. > > One should note that environment seriously affects MTBF, even on > non-movable parts, and probably even more on movable parts. Yes. Heat especially above all else. > I've talked to people in the reliability business, and they use models > that say that MTBF for a part at 20 C as opposed to 40 C can differ by a > factor of 3 or 4, or even more. A lot of people skimp on cooling and then > get upset when their drives fail. > > I'd venture to guess that a drive that has an MTBF of 1.2M at 25C will > have less than 1/10th of that at 55-60C. Yes. I know that full well. Therefore my server drives are mounted directly behind two monstrous 12cm fans... I don't take no risks. :-) Still, two western digitals have died within the first or second year in that enclosure. So much for MTBF vs. real world expectancy I guess. It should be public knowledge by now that heat is the number 1 killer for harddisks. However, you still see PC cases everywhere where disks are sandwiched together and with no possible airflow at all. Go figure... Maarten -- - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
