Thorsten Leemhuis wrote: > On 14.05.2007 12:53, Richard Hughes wrote: >> On Mon, 2007-05-14 at 10:37 +0100, Jonathan Underwood wrote: >>> There's another factor here though, as I understand it hard drive >>> lifetime is largely determined by the spin up/spin down frequency. So >>> while it may save a bit of power spinning down more often, this might >>> significantly shorten drive lifetimes. I'd definately want to have an >>> option to disable that, if my understanding is correct. >> Correct, hence why we only want to spin down the drive after a few >> hours, rather than minutes or seconds. > > Laptop drives are designed for lots of power spinning cycles (lots more > than server drivers for example). So spinning hard disks in laptops down > after 15 or 20 minutes should be totally fine afaics. Even after a > shorter timeframe (5 minutes) might be fine. But doing the same on the > server might destroy you hard disk quickly. You can get some numbers on it: random 3.5" desktop drive specifies a lifetime of 50,000 "start/stops" http://www.hitachigst.com/tech/techlib.nsf/techdocs/C5C895A725AC713E862571D5004E4EDB/$file/Deskstar_E7K500_DS.pdf Random 2.5" drive specifies a lifetime of 300,000 "load/unload cycles": http://www.hitachigst.com/tech/techlib.nsf/techdocs/D9DA661AA5D3E44B86256CEC0075C7B2/$file/Travelstar5K80-Datasheet.pdf The 3.5 drive quotes a "low duty cycle" MTBF of 114 years ;-) but I don't think the flash holding the firmware will last that long. If in reality you expected the drive to last 5 years and it was in use half that time, spreading the budget of 300,000 starts and stops over that period looks like you can afford to do something like 6 an hour... vs one an hour for the 3.5" drive... -Andy -- fedora-devel-list mailing list fedora-devel-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/fedora-devel-list
