From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Chmielewski Subject: Re: can I freeze I/O for some time to a given disk / md / dm Date: Tue, 07 Apr 2009 11:23:05 +0200 Message-ID: <49DB1B79.1070905@wpkg.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mx03.syneticon.net ([78.111.66.105]:33108 "EHLO mx03.syneticon.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750920AbZDGJXL (ORCPT ); Tue, 7 Apr 2009 05:23:11 -0400 Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Linux IDE , Gabor Gombas > On Tue, Dec 16, 2008 at 01:01:27PM +0100, Tomasz Chmielewski wrote: > >> Is it possible to "freeze I/O" for some time to a given disk / md / dm >> device? >> >> Say, "freeze I/O" so that userspace waits for any response for 30, 60 >> seconds or more? > > For real disks you can use /sys/block/sdX/device/unload_heads to achieve > something similar (see Documentation/laptops/disk-shock-protection.txt > in the kernel source about how to use it). That won't work for md/dm > devices though. For drives which don't support "unload_heads" plain hdparm should work: hdparm -Y /dev/sdX (possibly repeated in a loop for some time). -- Tomasz Chmielewski http://wpkg.org