lzma compression on official isos vs Deltaisos

[Bruno Wolff III]

On Wed, Mar 10, 2010 at 16:06:35 +0100,
  Roberto Ragusa <mail at robertoragusa.it> wrote:
> Bruno Wolff III wrote:
> > I did test an lzma compressed live image (non-functional due to no kernel
> > support) for the games spin and found it was 10% (400 MiB) smaller than
> > the zlib compressed version.
> 
> Isn't the basic strength of lzma a very big dictionary window?
> I would have said this is not easily paired to random access (squashfs).
> 10% (of the compressed size) looks like a very good gain.

I haven't done performance testing on live images. It is claimed that lzma
decompresses at good speeds compared to other options.
My expectation is reduced accesses to slow media (especially CDs and DVDs)
will outweigh other effects.
I have been holding off on testing things that need kernel support. If Kyle
lets me get squashfs 4.1 in rawhide or F13 and Lougher posts a revised
set of patches that will work with his clean up patches that have already
been pulled, then I'll look at doing some testing of live images and mounted
file systems. I wasn't planning on detailed benchmarks for that, just seeing
if things obviously sucked compared to zlib.