[D-I] The impact of a new language on Debian Installer

[Christian Perrier <bubulle@debian.org>]

I have made some tests to check what is the exact impact of a new
language added to Debian Installer.

The procedure was the following:

- identify which packages included in a netboot i386 initrd are
  localised

- recompile these packages from a fresh d-i checkout

- in another branch, run l10n-sync after commenting the new language
  in packages/po/PROSPECTIVE. This adds all xx.po files to the d-i
  packages

- activate this language in languagechooser

- recompile the initrd packages from that branch

- in both checkouts:
  - copy the recompiled udebs to "localudebs" in installer/build
  - "make build_netboot"

Then I compared the size of the uncompressed initrd images.

The result when activating Vietnamese is:

-rw-rw-r--  1 bubulle bubulle 8567808 2005-04-29 22:22 initrd-novi-trunk
-rw-rw-r--  1 bubulle bubulle 8585216 2005-04-29 22:22 initrd-vi

As we see, adding the Vietnamese language has added 174087 bytes to the
initrd. 

So, as a rough estimate, we can probably assume that adding a language
costs us about 18kb in the initrds.

About the memory impact:

I have booted mini.iso images in qemu up to the languagechooser
screen. Then I switched to VT2 and issued the "free" command:

With Vietnamese: 15524kb of memory are used
Without        : 15460kb of memory are used

At kbd-config step:

With           : 15580
Without        : 15520

At ethdetect step (I can't go further as for some reason my mini.iso
fails to load the net driver):

With           : 15756
Without        : 15716

So, funnily, the difference seems to decrease with the progress of the
various steps...:). Joey probably had a good explanation for that, but
indeed it seems to me that the major impact is on initrd sizes but it
is still quite manageable.


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