LargerLivefs

Differences between revisions 6 and 12 (spanning 6 versions)
Revision 6 as of 2006-06-22 17:23:51
Size: 2419
Editor: ALagny-109-1-2-101
Comment: expand on ISO building process some more
Revision 12 as of 2008-08-06 16:35:52
Size: 3707
Editor: localhost
Comment: converted to 1.6 markup
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 * '''Created''': [[Date(2006-06-21T16:49:29Z)]] by TollefFogHeen
 * '''Contributors''': TollefFogHeen
 * '''Created''': <<Date(2006-06-21T16:49:29Z)>> by TollefFogHeen
 * '''Contributors''': TollefFogHeen, ColinWatson, HenrikOmma
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Some less-used languages have users too.  They should be able to use the live DVD in their native tongue without having to resort to custom live CDs or similar solutions. Some less-used languages have millions of potential users too. They should be able to use the live DVD in their native tongue without having to resort to custom live CDs or similar solutions. For those who use voice sythesis applications, the language files are even larger. We are likely to include more media content in the future, in the form of audio, video and images. This will not fit on the CD while this spec would provide a flexible way for adding it to the DVDs.
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 * Daniella is a teacher in a remote school without broadband who uses Edubuntu in the classroom. She is happy to see that the Edubuntu DVD now contains a 500MB excerpt from wikipedia that she can test and optionally install.
 * Hans wants to try Ubuntu with German speech synthesis before installing. The Live CD only contains the 500kb reduced quality Espeak synth. He is happy to discover that booting the DVD in German+Screen reader modes, loads the 30mb German Festival voice with excellent quallity.
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The ISO building process currently `wget`s the live filesystem image from the buildd for each architecture, and places them in `/casper/filesystem.squashfs` on the ISO image. Following LiveCDStackedFileSystem, it will be changed to `wget` base, desktop, and live stacked filesystems, and place them in numerically-prefixed files under `/casper`, e.g. `/casper/05base.squashfs`, `/casper/10desktop.squashfs`, and `/casper/15live.squashfs`. To deal with this specification, it will be changed for DVD builds to `wget` the language pack filesystem image as well and place it in e.g. `/casper/20langpacks.squashfs` on the ISO image. If no language pack filesystem image is available, it will degrade to using only the normal live filesystem images. The ISO building process currently `wget`s the live filesystem image from the buildd for each architecture, and places them in `/casper/filesystem.squashfs` on the ISO image. Following [[LiveCDStackedFileSystem]], it will be changed to `wget` base, desktop, and live stacked filesystems, and place them in numerically-prefixed files under `/casper`, e.g. `/casper/05base.squashfs`, `/casper/10desktop.squashfs`, and `/casper/15live.squashfs`. To deal with this specification, it will be changed for DVD builds to `wget` the language pack filesystem image as well and place it in e.g. `/casper/20langpacks.squashfs` on the ISO image. If no language pack filesystem image is available, it will degrade to using only the normal live filesystem images.

== What could go wrong and how to handle it? ==

This spec depends on the live-cd-stacked-filesystem spec which has a certain risk associated with it. If we are unsuccessful in implementing the live-cd-stacked-filesystem spec, this spec can still be solved by just building a very large live fs. We really want to avoid that as it will require a lot more resources than a stacked file system approach, but is mentioned here for completeness

Summary

As of Ubuntu 6.06 LTS, an identical live filesystem is used on Ubuntu DVDs and CDs. Since space on the CD is limited, this filesystem omits translations and language support infrastructure for many languages. These packages should be available on the DVD, where more space is available.

Note that the casper side of this will Just Work when https://launchpad.net/distros/ubuntu/+spec/live-cd-stacked-filesystems is done.

Rationale

Some less-used languages have millions of potential users too. They should be able to use the live DVD in their native tongue without having to resort to custom live CDs or similar solutions. For those who use voice sythesis applications, the language files are even larger. We are likely to include more media content in the future, in the form of audio, video and images. This will not fit on the CD while this spec would provide a flexible way for adding it to the DVDs.

Use cases

  • Peter is a Swedish user who would like to try Ubuntu. Since Swedish isn't a common enough language to make it onto the install CDs, he downloads the live DVD and tries out Ubuntu in Swedish.
  • Daniella is a teacher in a remote school without broadband who uses Edubuntu in the classroom. She is happy to see that the Edubuntu DVD now contains a 500MB excerpt from wikipedia that she can test and optionally install.
  • Hans wants to try Ubuntu with German speech synthesis before installing. The Live CD only contains the 500kb reduced quality Espeak synth. He is happy to discover that booting the DVD in German+Screen reader modes, loads the 30mb German Festival voice with excellent quallity.

Scope

Affects the live filesystem and live ISO build process.

Design

Make livecd.sh build stacked file systems by mounting the previously built file systems and then installing the new set of packages. We will need a live-dvd seed or something similar to decide what goes onto the live DVD filesystem.

Implementation

livecd.sh needs to build the language pack/DVD live fs on top of the regular squashfs and make that available beside the regular livefs.

The ISO building process currently wgets the live filesystem image from the buildd for each architecture, and places them in /casper/filesystem.squashfs on the ISO image. Following LiveCDStackedFileSystem, it will be changed to wget base, desktop, and live stacked filesystems, and place them in numerically-prefixed files under /casper, e.g. /casper/05base.squashfs, /casper/10desktop.squashfs, and /casper/15live.squashfs. To deal with this specification, it will be changed for DVD builds to wget the language pack filesystem image as well and place it in e.g. /casper/20langpacks.squashfs on the ISO image. If no language pack filesystem image is available, it will degrade to using only the normal live filesystem images.

What could go wrong and how to handle it?

This spec depends on the live-cd-stacked-filesystem spec which has a certain risk associated with it. If we are unsuccessful in implementing the live-cd-stacked-filesystem spec, this spec can still be solved by just building a very large live fs. We really want to avoid that as it will require a lot more resources than a stacked file system approach, but is mentioned here for completeness


CategorySpec

LargerLivefs (last edited 2008-08-06 16:35:52 by localhost)