In message <Pine.NEB.3.95.970701163459.26673Y-100000@beech.pd.tgi.plexus.com> you wrote:

> On Tue, 1 Jul 1997, Andreas Brusinsky wrote:
> 
> > Is there a compressed filesystem for unix available? 
> > So that a compile process just acts inside of a tar file or so. 
> 
> Well, the idea is interesting, but I can only imagine this being practical
> if it's a read-only filesystem that you could layer something else on top
> of.  I'm not sure it's really worth the effort, though... you'd certainly
> take a significant performance hit.

I'm using an Acorn RiscPC with NetBSD-arm32 and RiscOS, the original 
OS by Acorn. RiscOS has a concept called "image file-systems", which 
means that you can load "modules" (OS extensions, sort of) that 
declare themselves as filesystems for a particular filetype (there's
true, ie non-extension-based filetypes in RiscOS).

This file, once the module has initialised, now looks like a directory
to the user. 
There's several uses for this, the most used option is perhaps 
"SparkFS", a thirdparty app that can handle some native compression
formats as well as a number of standard-archive formats like zip and
tar as filesystems - very handy to just try out an archive. 

This works quite well on RiscOS and is a feature I wouldn't like to miss
at all.

However, I think that for Unix this isn't the same. First, it's quite 
obvious that once you've got to write to the image file, it's getting
very slow. While RiscOS is quite independent of harddisk usage (you 
*could* use it with a floppy disc), I think that's not true for 
Unix in general. Also, how would you mount such image filesystems ?
You've either got to mount everyone manually, or you'd have to write 
an automounter, don't you ?

Kind regards,

-- 
Thomas Boroske