Install CD with lzma compression

Phillip Susi psusi at
Thu Jan 5 01:38:59 GMT 2006

It _works_?  Did you patch dpkg to support 7zip inside the debs?  Could 
you maybe repackage dpkg with that support and put it on revu or 
something?  Also I am not sure, but I don't think the signatures woule 
be made invalid by changing the compression.  The data files are all 
checked via their md5 sum, which would remain the same once extracted, 
and the control file that lists their md5 sums also would be the same 
once extracted, and it is that file that is signed ( I believe ).

Christian Leber wrote:
> Hello,
> I was wondering how much space could be saved with replacing the .gz
> compression with lzma, so i tried it and the result ist:
> -rw-r--r--  1 ijuz ijuz 501211136 Jan  4 14:43 ubuntu-breezy-lzma-poc-01.iso
> you can download it here:
> (just a "proof-of-concept") (MD5 73bdf44abc204a4fcfebf902861243c7)
> compared to:
> -rw-r--r--  1 ijuz ijuz 647129088 2005-10-13 11:14 ubuntu-5.10-install-i386.iso
> All data is included, i only recompressed the gzip compressed .deb packages
> with lzma, i didn't know that some (the language packs) are compressed
> with bzip2. And the udeb's are also not compressed with lzma because for
> some reason there was some md5 error that i can't find.
> (this measures would save additional 21 MB)
> The Installation from CD works, after the reboot for some reason
> ubuntu-desktop isn't installed automatically, i think that is because
> the gpg signature isn't correct anymore obviously.
> But i removed all other sources besides the CD from the sources.list and
> was able to apt-get install ubuntu-desktop.
> I can upload the patches if somebody is interested.
> Cheers,
> Christian

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