Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759256AbWK3QYa (ORCPT ); Thu, 30 Nov 2006 11:24:30 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759257AbWK3QYa (ORCPT ); Thu, 30 Nov 2006 11:24:30 -0500 Received: from ug-out-1314.google.com ([66.249.92.169]:59673 "EHLO ug-out-1314.google.com") by vger.kernel.org with ESMTP id S1759256AbWK3QY3 (ORCPT ); Thu, 30 Nov 2006 11:24:29 -0500 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:cc:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references; b=aMxazSe6Ku1EuoQK1tHfadbZUnCIudIXYPNp9mhJIifhghmiGyWrKv0OnZO3Sv28vq2EGlceAJMw48AIfE1rJh/9m9FlxI6KfPv/5g8RoSMB3QPgGwG2tPrgPGsE7wCuhOGWJGk2qprfphXl3eTGWGo+wBSKwGXuzxu73rbOyRY= Message-ID: Date: Thu, 30 Nov 2006 10:24:27 -0600 From: "Eric Van Hensbergen" To: "device-mapper development" Subject: Re: [dm-devel] [RFC][PATCH] dm-cache: block level disk cache target for device mapper Cc: "Eric Van Hensbergen" , ming@acis.ufl.edu, linux-kernel@vger.kernel.org In-Reply-To: <200611301232.57966.jens.wilke@de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200611271826.kARIQYRi032717@hera.kernel.org> <200611301232.57966.jens.wilke@de.ibm.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1139 Lines: 24 On 11/30/06, Jens Wilke wrote: > On Monday 27 November 2006 19:26, Eric Van Hensbergen wrote: > > If this is intended to speed up remote disks, is it possible that the cache content > can be paged out on local disks in low-mem situations? > The main intent was to use local disks as cache to offload centralized remote disks. The logic was that most systems have local disks, if only for swap -- so why not use them as a cache to help offload centralized storage. While the in-memory page cache works perfectly fine in certain situations -- we were dealing with workloads in which the in-memory page-cache wasn't sufficient to hold all the data. There are also some additional possibilities we've thought through and have been playing with including allowing the local disk cache to be persistent across reboots (with varying validation schemes). -eric - 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/