From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ming Zhang Subject: Re: Device Mapper as a cache for SAN? Date: Mon, 10 Apr 2006 17:25:25 -0400 Message-ID: <1144704325.8591.170.camel@localhost.localdomain> References: <20060410184531.GA12908@www.ewilts.org> Reply-To: mingz@ele.uri.edu, device-mapper development Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: device-mapper development List-Id: dm-devel.ids On Mon, 2006-04-10 at 14:46 -0500, Eric Van Hensbergen wrote: > On 4/10/06, Ed Wilts wrote: > > > > The obvious question is why? What would this provide that the kernel > > and file systems don't already provide? > > > > Well, kernel provides in-memory page cache, not local disk page cache. > There is some ongoing remote file system local disk cache work being > done, but it applies primarily to AFS and NFS - not block-based > transports such as iSCSI and AOE. The various cluster file systems > may provide something more akin to this, but again, this doesn't > really cover SAN technologies -- not in any sort of a generic way. > Let me know if I'm missing something. still, what is the main benefit of this cache? what u mean "local disk page cache"? use "local disk" as page cache or page cache for "local disk" or something else? ming > > -eric > > -- > dm-devel mailing list > dm-devel@redhat.com > https://www.redhat.com/mailman/listinfo/dm-devel