From mboxrd@z Thu Jan 1 00:00:00 1970 From: Elias Oltmanns Subject: Re: [PATCH 4/4 v2] Add documentation for hard disk shockprotection interface Date: Fri, 19 Sep 2008 11:50:51 +0200 Message-ID: <87iqssmpl0.fsf@denkblock.local> References: <87d4j2n3dn.fsf@denkblock.local> <20080917163145.9870.8575.stgit@denkblock.local> <1221724782.3261.13.camel@raz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from nebensachen.de ([195.34.83.29]:45154 "EHLO mail.nebensachen.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751153AbYISJw3 (ORCPT ); Fri, 19 Sep 2008 05:52:29 -0400 Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Raz Ben-Yehuda Cc: linux-ide@vger.kernel.org [ For some reason your email has not shown up on linux-ide. ] "Raz Ben-Yehuda" wrote: > Elias > looks very interesting. > 1. How will it impact VM , swappers , raids ? What exactly do you want to know? As long as the disk is parked, you can do no I/O on it, i.e. no swapping is possible. Since I don't know anything about the implementation of raids and don't have a raid setup here, I can't really tell how a raid device will behave exactly when one of its disks has been parked. Generally, all I/O will be delayed until the disk is unparked again. > 2. you said it has no value for servers ? did you try ? Again, I'm not quite sure what you want to know. Obviously, desktops or servers for that matter can have disks installed that support the unload feature. On these devices you can use the interface as described in my document. All I'm saying is that the interface has been designed with laptops in mind because I don't see in which situation immediate head unloading would be required or even desirable in a classical server environment. Regards, Elias