From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: better solution for frequent head unload problem Date: Wed, 01 Oct 2008 02:58:45 +0900 Message-ID: <48E268D5.2090709@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from hera.kernel.org ([140.211.167.34]:42189 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752061AbYI3SAy (ORCPT ); Tue, 30 Sep 2008 14:00:54 -0400 Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Bruce Allen , IDE/ATA development list Cc: Robert Krawitz , Carlos Bessa , aladin7501-01@yahoo.de, webmaster@dragontower.de, "Ivan N. Zlatev" , aliencoder@gmail.com, pascal@asmodeus.be, andrew.vaselaar@trinity.edu"Ivan N. Zlatev" , aklitzing@online.de, Christian Wolf Hello, Bruce and cc'd reporters. I'm having a second thought about storage-fixup as solution for frequent head unload problem. Initially, I thought there would be only a handful of affected machines but it doesn't look like that anymore and storage-fixup is too inflexible. IMHO, this can be best dealt with by smartd if it can do the followings. * smartd knows about most drive families - their l/ul limits and which value to use to disable APM. * it monitors u/ul limits and if the load count increases fast enough that the drive reaches the limit before 1.5 years of uptime (or some other value), it warns and automatically disables APM. By doing the above, we don't have to maintain list of combinations of system and harddrives which can never be complete and later when the disk workload becomes different due to FS or VM changes, the powersaving feature can be left enabled. Obstacles are... * How to build rather complete SMART database? I think vendor cooperation is necessary. If we can work out something, it will also improve general usefulness of SMART. * Making distros enable smartd by default. smartd might need a bit of adjustment but I think this shouldn't be too difficult. What do you think? Till we can figure out something, I'll keep building storage-fixup.conf. Thanks. -- tejun