From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bill Davidsen Subject: Re: RAID Class Drives` Date: Sat, 20 Mar 2010 13:26:21 -0400 Message-ID: <4BA5053D.1040607@tmr.com> References: <7db987b31003170648j19e3346bi1050e703ef8c811c@mail.gmail.com> <4BA258AD.5020605@gmx.net> <4BA33284.7000304@anonymous.org.uk> <4BA3BA1D.50206@gmx.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <4BA3BA1D.50206@gmx.net> Sender: linux-raid-owner@vger.kernel.org To: Joachim Otahal Cc: John Robinson , linux-raid@vger.kernel.org List-Id: linux-raid.ids Joachim Otahal wrote: > John Robinson schrieb: >> On 18/03/2010 16:45, Joachim Otahal wrote: >>> [...] You should take care of the temperature of the drives, >>> 30=B0C to 35=B0C is preferred, above 35=B0C the lifespan goes down,= over=20 >>> 40=B0C rapidly down. >> >> Do you have a reference for this? Most drives' operating temperature= =20 >> range is specified up to 55=B0C, sometimes higher for enterprise=20 >> drives, without any indication (apart from common sense perhaps) tha= t=20 >> running them this hot reduces lifespan. >> >> Cheers, >> >> John. >> > About a half year ago the german publisher c't did this testing (or=20 > reported from a big testing, cannot remember) what the best=20 > temperature of desktop drives is. The statistic varied from drive to=20 > drive since some are less than 5=B0C over room temperature, others ar= e=20 > 15=B0C or more over room temperature (of course mounted behind a sile= nt=20 > fan which keeps the air moving, no turbine mode). > The result was that 10=B0C and 15=B0C are not good for the drives. Th= e=20 > "perfect sweet spot" changes from drive to drive (even within on=20 > manufacturer), but all of them had their sweet spot somewhere around=20 > 20=B0C to to 35=B0C with variation in the range of measurement error. > Some drives has a higher failure rate at 40=B0C, for some 55=B0C was = no=20 > problem at all and showed no real change in the failure rate. The las= t=20 > two examples were the extreme cases. > > Some of my drives are 2=B0C above room temperature, others are 12=B0C= over=20 > room temperature. Sine I really take care that non reaches 40=B0C eve= n=20 > in summer the failure rate got down from "every few month" to once in= =20 > the 3 years which is the time I really take care of the drive=20 > temperatures. There are 6 drives currently in use from 750GB (the=20 > hottest of all my drives) up to 1.5 TB in my private machines, only=20 > one of them shows a gradual change in the SMART values (reallocated=20 > sector count), which mean it will probably fail in about 1.5 years if= =20 > the error rate stays constant. At work (at least the two machines 100= %=20 > under my control) I had the same effect, keep the HD's cool and they=20 > will live long, let them get over 40=B0C and be ready to replace them= soon. 40=B0C is a good target, readily available to people in the Arctic. It=20 requires a lot of cooling to do it in normal climates where the ambient= =20 may be mid to high 40s. Fortunately my experience looks more like=20 Google's, as long as you move enough air over the drive to avoid hot=20 spots they seem to do well, hitting 43-46 much of the time. If I replac= e=20 them because they're obsolete and working, they lasted long enough.=20 Perhaps being "always on" is part of longevity, the ones I have on for=20 5-6 years seldom fail, the desktop cycled daily maybe half that. I do note that the WD drives run about 8=B0C cooler than Seagate. That'= s=20 the "black" drive, I guess, the "green" drives would run cooler, based=20 on power use. I will switch to them next build. --=20 Bill Davidsen "We can't solve today's problems by using the same thinking we used in creating them." - Einstein -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html