[dm-devel] Re: [RFC][PATCH] dm-cache: block level disk cache target for device mapper

[Christoph Hellwig <hch infradead 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?