From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kris Van Bruwaene Subject: Re: Can compression at filesystem level improve overall performance? Date: Mon, 22 Mar 2004 09:01:28 +0100 Message-ID: <405E9D58.6080404@vrt.be> References: <405B02ED.4010602@solidcode.net> <1079713790.9729.1.camel@redeeman.linux.dk> <16475.9613.375262.677576@laputa.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: <16475.9613.375262.677576@laputa.namesys.com> List-Id: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Nikita Danilov Cc: Reiserfs Mailinglist Nikita Danilov wrote: >Redeeman writes: > > On Fri, 2004-03-19 at 15:25, Erik Terpstra wrote: > > > Is it fair to say that today compression at the filesystem level would > > > improve overall performance? > > the more agressive you compress it the more cpu it takes, and that will > > make it slower, but i think a small compression algorithm for filesystem > > purpose could be written... however, i doubt it will be worth it, > > harddrives are really cheap nowadays.. but maybe some algortihm to > > compress cleartext only, or something.. > >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. > > Something else to consider: the gain might not be so impressive, since many files are already heavily compressed: apart from the obvious ones (.zip .gz .bz2) most audio (.mp3) and video is natively compressed (mpeg2/4), and amy office files as well (presentations, pdf...).