From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans Reiser Subject: Re: Can compression at filesystem level improve overall Date: Mon, 22 Mar 2004 12:14:02 +0300 Message-ID: <405EAE5A.8020600@namesys.com> References: <200403212317.i2LNHrJo010166@sirius.cs.pdx.edu> Reply-To: reiser@namesys.com Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: list-help: list-unsubscribe: list-post: Errors-To: flx@namesys.com In-Reply-To: <200403212317.i2LNHrJo010166@sirius.cs.pdx.edu> List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: reiserfs-list@namesys.com Cc: sean@gutenpress.org, Edward Shishkin The Amazing Dragon (Elliott Mitchell) wrote: >>From: Sean Johnson >>On Fri, 2004-03-19 at 11:53, Nikita Danilov wrote: >> >> >>>That's common misconception. :) >>> >>>The goal of compression is to conserve disk bandwidth rather than space. >>> >>>By compressing it is possible to transfer data (== uncompressed data >>>user works with), at a rate higher than raw device bandwidth. >>> >>> >>I am far from any kind of authority on filesystems, but doesn't compression >>make data corruption a significantly nastier bugaboo? >> >> > >Potentially. Depending upon the encoding losing one block of encoded data >maps to losing many blocks of decoded data. Also losing the first block >of data might make it impossible to recover later blocks. > > I think it will just make you lose the compression atom, but Edward can say more when he gets back from vacation. >But these aren't issues since you do error correction near the physical >layer, and backups just you make sure. You do, don't you? > > > > -- Hans