From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [RFC][PATCH] dm-cache: block level disk cache target for device mapper Date: Thu, 30 Nov 2006 14:48:07 +0000 Message-ID: <20061130144807.GA16474@infradead.org> References: <200611271826.kARIQYRi032717@hera.kernel.org> Reply-To: device-mapper development Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <200611271826.kARIQYRi032717@hera.kernel.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: Eric Van Hensbergen Cc: dm-devel@redhat.com, ming@acis.ufl.edu, linux-kernel@vger.kernel.org List-Id: dm-devel.ids On Mon, Nov 27, 2006 at 06:26:34PM +0000, Eric Van Hensbergen wrote: > This is the first cut of a device-mapper target which provides a write-back > or write-through block cache. It is intended to be used in conjunction with > remote block devices such as iSCSI or ATA-over-Ethernet, particularly in > cluster situations. > > In performance tests with iSCSI, gave peformance improvements of 2-10x that > of iSCSI alone when Postmark or Bonnie loads were applied from 8 clients to > a single server. Evidence suggests even greater differences on larger > clusters. A detailed performance analysis will be vailable shortly via a > technical report on IBM's CyberDigest. > > This module was developed during an intership at IBM Research by > Ming Zhao. Please direct comments to both Ming and myself. I don't quite understand the need for this. Do you need this module because your iscsi target doesn't use the pagecache on the server? From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S967409AbWK3OsL (ORCPT ); Thu, 30 Nov 2006 09:48:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S936434AbWK3OsL (ORCPT ); Thu, 30 Nov 2006 09:48:11 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:45511 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S936432AbWK3OsJ (ORCPT ); Thu, 30 Nov 2006 09:48:09 -0500 Date: Thu, 30 Nov 2006 14:48:07 +0000 From: Christoph Hellwig To: Eric Van Hensbergen Cc: linux-kernel@vger.kernel.org, dm-devel@redhat.com, ming@acis.ufl.edu, ericvh@gmail.com Subject: Re: [RFC][PATCH] dm-cache: block level disk cache target for device mapper Message-ID: <20061130144807.GA16474@infradead.org> Mail-Followup-To: Christoph Hellwig , Eric Van Hensbergen , linux-kernel@vger.kernel.org, dm-devel@redhat.com, ming@acis.ufl.edu, ericvh@gmail.com References: <200611271826.kARIQYRi032717@hera.kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200611271826.kARIQYRi032717@hera.kernel.org> User-Agent: Mutt/1.4.2.2i X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 27, 2006 at 06:26:34PM +0000, Eric Van Hensbergen wrote: > This is the first cut of a device-mapper target which provides a write-back > or write-through block cache. It is intended to be used in conjunction with > remote block devices such as iSCSI or ATA-over-Ethernet, particularly in > cluster situations. > > In performance tests with iSCSI, gave peformance improvements of 2-10x that > of iSCSI alone when Postmark or Bonnie loads were applied from 8 clients to > a single server. Evidence suggests even greater differences on larger > clusters. A detailed performance analysis will be vailable shortly via a > technical report on IBM's CyberDigest. > > This module was developed during an intership at IBM Research by > Ming Zhao. Please direct comments to both Ming and myself. I don't quite understand the need for this. Do you need this module because your iscsi target doesn't use the pagecache on the server?