Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753963Ab0L0SUo (ORCPT ); Mon, 27 Dec 2010 13:20:44 -0500 Received: from inx.pm.waw.pl ([195.116.170.130]:60445 "EHLO inx.pm.waw.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752378Ab0L0SUm (ORCPT ); Mon, 27 Dec 2010 13:20:42 -0500 From: Krzysztof Halasa To: Mark Knecht Cc: Jeff Moyer , Rogier Wolff , Greg Freemyer , Bruno =?utf-8?Q?Pr=C3=A9mont?= , linux-kernel@vger.kernel.org, linux-ide@vger.kernel.org Subject: Re: Slow disks. References: <20101220141553.GA6088@bitwizard.nl> <20101220190630.66084e1d@neptune.home> <20101222104306.GB30941@bitwizard.nl> Date: Mon, 27 Dec 2010 19:20:24 +0100 In-Reply-To: (Mark Knecht's message of "Sun, 26 Dec 2010 15:38:51 -0800") Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1062 Lines: 25 Mark Knecht writes: > Even when I got that part worked out I found that the drives just > didn't work well in a RAID. The mdadm list led me to believe that the > root cause was the lack of TLER in the firmware. I don't know how to > show that's true or not... But TLER only matters when the drive can't read a sector. For a normal drive which can easily read all its sectors (at least without retrying for several seconds) TLER doesn't matter. Alignment, sure. Personally I'd use whole disks (not partitions) for RAID-5 and partition the resulting /dev/md* instead, taking into account even longer "sector" size. Or better, use RAID-1 (or RAID-10) with 4 KB block fs, partition /dev/md* with 4 KB alignment, and avoid all these issues. Disks aren't that expensive now. -- Krzysztof Halasa -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/