From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Hendrikx Subject: Re: Save to use spindown? Date: Sun, 22 Jan 2006 03:10:46 +0100 Message-ID: <43D2E9A6.8000703@xs4all.nl> References: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Mark Hahn wrote: > you seem to be assuming that the drives have a lifespan measured in > hours-spinning. that's not at all clear. for instance, drives > are typically rated 40-50K start-stop cycles, which is ~40/day > over a 3-year service life. > > you clearly do not want to auto-spindown unless you are sure that > they'll spun-down for a fairly long time. even ignoring delay in > spinup... > Hm, 40-50k start-stop cycles? That's far more than I would have thought. I always figured that my hard drives would live longer if I kept them spinning instead of spinning them down even once a day. Most of my drives at the moment are below 10 start-stop cycles, even though the array is only used very lightly for a few hours every day. It sounds to me it might not be a bad idea for me to spin the drives down in my case. >> that good. Too many things running on your server will keep them going - >> eg. ext3 likes to peek at the drives every 5 seconds (and it's probable >> that other journaling FS's to some extent or other). >> > > I don't believe ext3 will generate journal forces unless you do something > that generates data or journal IO. for instance, atime updates are often > overlooked here. I generally turn atime stuff off anyway. > But accessing the drive will spin it up anyway, so why would it be prudent to turn atime off (apart from the fact that it is often not needed anyway)? --John