From mboxrd@z Thu Jan 1 00:00:00 1970 From: Khelben Blackstaff Subject: Re: Use of WD20EARS with MDADM Date: Thu, 22 Apr 2010 19:13:50 +0300 Message-ID: <201004221913.50692.eye.of.the.8eholder@gmail.com> References: <4BAB8D41.4010801@gmail.com> <4BCF4693.3020101@buttersideup.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4BCF4693.3020101@buttersideup.com> Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids > I believe that these disks only come in the "green" variety. I recently > 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 drives > firmware automatically parks the head after 8 seconds of inactivity and > reduces the rpm of the disk. The constant parking can quickly wear 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. > 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. Granted that is about worst case, but still something to > watch out for. In order to make it the entire 3 year warranty period, > you need to stay under 11.4 unloads per hour. If you have very little > 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 drives were validated to 1M load/unload cycles and not 300K. > > If you want to fix it, then wdidle3.exe worked for me. Search for: > > wdidle3_1_00.zip > It worked fine for me too. I had a Load Cycle Count of 59, 15 mins after connecting the drive for the first time. After running wdidle the Count stopped at 104 and never increased again. I now have 11 hours With wdidle 1.00 disabling the timer did nothing. I had to set the timer to a large value. There is a newer version though (1.03) that supports these new drives better.