Proposal for solving CD Size problems

[Christian Leber]

On Wed, Sep 27, 2006 at 04:12:25PM -0400, Tim Schmidt wrote:
> > The saving is under 8%, and the performance hit is extremely noticeable
> > (at least within VMware), it takes almost twice the time to boot.
> 50Mb is nothing to sneeze at...  Although, it's not 100Mb.  Any idea
> if the lzma code can be optomized any better than it already is?

It's more, i compressed the Knot-3 live-cd with lzma:

-r--r--r--  2 root root 599M 2006-09-15 11:39 /media/cdrom0/casper/filesystem.squashfs
-rwx------  1 root root 529M 2006-09-27 15:14 mnt.squashlzma

And yes, it can be optimized more:
LzmaDecode.h

+/* #define _LZMA_PROB32 */
+/* It can increase speed on some 32-bit CPUs, 
+   but memory usage will be doubled in that case */
+
+/* #define _LZMA_LOC_OPT */
+/* Enable local speed optimizations inside code */

should be uncommented

Compressing with -O3 also helps a lot for lzma.

> Can you make a cd image built with lzma availabe for download, so a
> few of us can test it on actual hardware?

This old Knoppix version with lzma compressed is here:
http://debian.christian-leber.de/~ijuz/knoppix_lzma_v0.2.iso
As said, it was like 94 against 101 sec for me.

Finding the right kernel etc. would surely take me hours.


Christian Leber

-- 
http://rettetdieti.vde-uni-mannheim.de/