From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 29 Jun 2001 05:51:22 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 29 Jun 2001 05:51:12 -0400 Received: from router-100M.swansea.linux.org.uk ([194.168.151.17]:59140 "EHLO the-village.bc.nu") by vger.kernel.org with ESMTP id ; Fri, 29 Jun 2001 05:50:58 -0400 Subject: Re: O_DIRECT please; Sybase 12.5 To: dank@kegel.com (Dan Kegel) Date: Fri, 29 Jun 2001 10:50:15 +0100 (BST) Cc: linux-kernel@vger.kernel.org (linux-kernel@vger.kernel.org) In-Reply-To: <3B3C4CB4.6B3D2B2F@kegel.com> from "Dan Kegel" at Jun 29, 2001 02:39:00 AM X-Mailer: ELM [version 2.5 PL3] MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-Id: From: Alan Cox Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > the boss say "If Linux makes Sybase go through the page cache on > reads, maybe we'll just have to switch to Solaris. That's > a serious performance problem." Thats something you'd have to benchmark. It depends on a very large number of factors including whether the database uses mmap, the average I/O size and the like > It supports raw partitions, which is good; that might satisfy my > boss (although the administration will be a pain, and I'm not > sure whether it's really supported by Dell RAID devices). > I'd prefer O_DIRECT :-( We already support raw direct I/O to devices themselves so they should support that - if not then Oracle I believe already does.