More LiveCD space optimizations

[Louis Simard]

2010-10-07 16:07 GMT John McCabe-Dansted <gmatht at gmail.com>:
> On Thu, Oct 7, 2010 at 10:05 AM, Louis Simard <louis.simard at gmail.com> wrote:
>> Do you want me to add to my script any of the optimisations discussed
>> in your email? They are: Using AdvanceCOMP to recompress .png images
>> and gzipped files; using either of jpegoptim or jpegrescan to
>> losslessly recompress .jpg images; "transcoding" man pages from .gz to
>> .lzma. I'm not going to add untested optimisations yet, such as
>> transcoding *all* .gz files to .lzma.
>
> Sure. This could help with testing that these actually work ;).

It works! :) 'man' reads its files correctly, after an addition to the
script to fix the broken symlinks (for example, zfgrep.1.gz pointing
to zgrep.1.gz in /usr/share/man/man1 which became zgrep.1.lzma),
OpenOffice.org opens the Human icons correctly, all of the PNG images
compare equal using pngtopnm (although some emit a warning about the
pixel aspect ratio, i.e. non-square pixels) and Java is able to read
.jar files that have been recompressed.

However, while recompressing the files helped the ISO size, it made
the install size grow by about 180 MB...

When | ISO size (B) | Install (KiB)
------------------------------------
 Old |  718,864,384 |     2,293,740
 New |  711,032,832 |     2,474,660

Ow! What's going on?

Here's the methodology I used for that result.
* The base CD is Ubuntu 10.04.1.
* Using the virtual hardware provided by VirtualBox OSE 3.1.6 r59338,
384 MB RAM, 5 GB SCSI hard drive and IDE CD-ROM drive using the ISO.
* Look at the size of the CD ISO using ls -l.
* Using 'df', look at the number of disk blocks used on the VM's hard
drive before rebooting from an installation via the GUI:
a) Language: English
b) Time zone: Europe/United Kingdom Time
c) Keyboard layout: USA
d) Disk space preparation: Manual partitioning, no swap, fill the
entire drive with an ext4 partition for /
e) Username, password and computer name: "dummy"

Attached are the scripts I used to mount the original CD, recompress
the files and make the new CD.

No CDs were harmed in the making of this email.

- Louis
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