Re: Can compression at filesystem level improve overall performance?

[Kris Van Bruwaene]

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...).