From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Subject: Re: max_sectors in libata when using md Date: Thu, 26 Aug 2004 08:52:48 -0700 Sender: linux-raid-owner@vger.kernel.org Message-ID: <8746466a0408260852205a7842@mail.gmail.com> References: <412DFFA9.8030504@wasp.net.au> Reply-To: Dave Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <412DFFA9.8030504@wasp.net.au> To: Brad Campbell Cc: linux-ide@vger.kernel.org, SCSI Mailing List , RAID Linux List-Id: linux-ide@vger.kernel.org On Thu, 26 Aug 2004 19:20:09 +0400, Brad Campbell wrote: > G'day all, > > Hot on the trail of this libata oddity. > > > ATA_MAX_SECTORS == 200. > > Should then the scsi layer be able to do this and queue 1/2 a Meg in a single request? > > Am I looking at something completely weird? Is the block layer doing something I should know about? > Can SATA transfers handle 1024 sectors in one go? Will Batman make it out of the cave alive? That is decimal 200, not hex 200. Technically with ATA (or SATA) drives you can bump it to 0x100 (256). That is the limitation of LBA28 drives. With LBA48 drives you can do 0xffff (64k) sectors per request I believe. I wish the SATA layer would allow a mechanism to auto detect drive being LBA48 or LBA28 and adjust accordingly instead of just default to a very low sector count. -- -= Dave =- Software Engineer - Advanced Development Engineering Team Storage Component Division - Intel Corp. mailto://dave-DOT-jiang-AT-intel-DOT-com ---- The views expressed in this email are mine alone and do not necessarily reflect the views of my employer (Intel Corp.).