From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan *St0fF* Huebner Subject: Re: Use of WD20EARS with MDADM Date: Sun, 28 Mar 2010 18:19:17 +0200 Message-ID: <4BAF8185.9040307@gmx.net> References: <4BAB8D41.4010801@gmail.com> <4BABA12D.6040605@shiftmail.org> Reply-To: st0ff@npl.de Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4BABA12D.6040605@shiftmail.org> Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Am 25.03.2010 18:45, schrieb Asdo: > David Lethe wrote: >> On Mar 25, 2010, at 11:20 AM, Andrew Dunn wrote: >> >>> Recently Dell is selling their WD20EARS (2TB) for 90$ >>> >>> This being one of the best PPG (Price Per Gigabyte) snatches I have >>> seen, I was considering buying 8 of them for an mdadm array. >>> >>> Has anyone had experience with these drives? >>> >>> Note, they have 4K sectors. >>> >>> Thank you for your kind responses. >>> -- >>> To unsubscribe from this list: send the line "unsubscribe >>> linux-raid" in >>> the body of a message to majordomo@vger.kernel.org >>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>> >> >> This is a low-cost consumer disk that is rated for a whole 2400 hours >> use in a year. You get what you pay for. > > I think the "I" in RAID stands for inexpensive :-P > Jokes apart, don't you think frequent scrubbing (e.g. weekly for a > raid-6 or 2/week for raid-1/10) is enough to compensate for this? > I would be way more concerned with ERC / TLER if it proves to be > nonsettable, but I might be wrong Just for those who like to read: ERC is a feature stated in the ATA-specifications, that's why the "quick hack" for smartctl was so easy. But in the specs it is also noted, that the change a SCT-ERC-Command does will not survive a power cycle. So y'all will probably need some udev-triggered daemon, which runs upon connecting a disk, checking if this disk is conforming to the ata-spec, then finding out if it's part of a raid array. If all answers yield "yes", it should call SCT-ERC with a configurable value, and probably some other "configure the drive"-commands (for tuning the idle timeout of wdXXears). I'll have to think about that as a project again ... All the best, Stefan > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html