From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Matthews Subject: Re: Use of WD20EARS with MDADM Date: Thu, 22 Apr 2010 11:16:38 -0700 Message-ID: References: <4BAB8D41.4010801@gmail.com> <4BCF4693.3020101@buttersideup.com> <201004221913.50692.eye.of.the.8eholder@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <201004221913.50692.eye.of.the.8eholder@gmail.com> Sender: linux-raid-owner@vger.kernel.org To: Khelben Blackstaff Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Thu, Apr 22, 2010 at 9:13 AM, Khelben Blackstaff wrote: >> I believe that these disks only come in the "green" variety. =A0I re= cently >> picked up a 1.5 tb version for testing and cheap bulk storage, and I >> would not suggest using them in a raid array because the green drive= s >> firmware automatically parks the head after 8 seconds of inactivity = and >> reduces the rpm of the disk. =A0The constant parking can quickly wea= r out >> the head under high use and there is no way to disable this "feature= ". > > As previously mentioned wdidle utility can disable the head unloading= =2E > >> The specifications say it's good for 300,000 cycles, so do the >> math... getting 5 unloads per minute would lead to probable failure >> after 41 days. =A0Granted that is about worst case, but still someth= ing to >> watch out for. =A0In order to make it the entire 3 year warranty per= iod, >> you need to stay under 11.4 unloads per hour. =A0If you have very li= ttle >> IO activity, or VERY MUCH, then this is entirely possible, but more >> moderate loads in the middle have been observed to cause hundreds of >> unloads per hour. > > WD mentions in the customer help (Answer ID 5357) that these newer dr= ives > were validated to 1M load/unload cycles and not 300K. > >> >> If you want to fix it, then wdidle3.exe worked for me. =A0Search for= : >> >> wdidle3_1_00.zip >> I just looked at a WD green drive that was in a RAID1 set for several months. The drive is an older model -- WD10EADS, but I think similar. I did not use the widdle utility and the S.M.A.R.T. data reports a load cycle count of 42. The RAID set held user directories, so it was either under constant access (daytime) or not at all (nighttime, apart from during backups). Simon -- 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