From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steve Lord Subject: 3ware driver maximum request size Date: Thu, 17 Aug 2006 10:13:03 -0500 Message-ID: <44E4877F.2070708@xfs.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail01hq.adic.com ([63.81.117.10]:38468 "EHLO MAIL01HQ.adic.com") by vger.kernel.org with ESMTP id S965127AbWHQPNF (ORCPT ); Thu, 17 Aug 2006 11:13:05 -0400 Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: linux-scsi@vger.kernel.org, aradford@gmail.com Does anyone know why the 3ware driver caps I/O at 128K bytes per scsi request? The driver defines a scatter gather array which will always cope with at least twice this. I am running with the TW_MAX_SECTORS constant at 512 and getting 256K I/Os to a 6+1 raid5 lun on a 9550SX. By my calculations this does not exceed the defined sizes of the scatter gather arrays for this type of device (but would I guess for the escalade variant in the code). I know nothing about the hardware itself, but if this works it seems like a worthwhile change for the newer devices. Thanks Steve Lord