LiveCDStackedFileSystem

Differences between revisions 1 and 5 (spanning 4 versions)
Revision 1 as of 2006-06-07 13:15:48
Size: 1390
Editor: 92
Comment: Initial framework
Revision 5 as of 2006-06-22 17:10:13
Size: 1914
Editor: ALagny-109-1-2-101
Comment: Fix up according to comments from Daniel
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 * '''Packages affected''':  * '''Packages affected''':  casper, live image build process
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 * John wants to create a customised live CD. He takes the base livefs and builds a custom squashfs with the packages he wants, then drops that into /casper on and burns it to a CD.
 * Ubuntu wants to have a DVD image with more language packs than what there's room for on a CD.  The livefs build process therefore creates a separate squashfs with just the language packs on and makes it available to the DVD build process.
 * John wants to create a customised live CD. He takes the base livefs and builds a custom squashfs with the packages he wants, then drops that into `/casper` and burns the whole structure to a CD.

* Ubuntu wants to have a DVD image with more language packs than would typically fit on a CD. The livefs build process therefore creates a separate squashfs with just the language packs in and makes it available to the DVD build process.
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== Design == Affects casper and to a smaller extent the live filesystem and live ISO image building process.
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== Implementation == == Design and implementation ==
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=== Code ===  * casper will look at `/casper/*.squashfs` in ASCII order and mount all the squashfs-es there with unionfs. The topmost layer will be a persistent device or just a tmpfs in the same way it currently is.
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=== Data preservation and migration === {{{dsilvers: Would 'run-parts order' be a more useful description than 'ASCII order' ?}}}
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== Outstanding issues == {{{tfheen: no, it's in for f in *.squashfs; ... ; done in a C locale order. }}}
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== BoF agenda and discussion ==  * livecd.sh and the live ISO build process is covered by https://launchpad.net/distros/ubuntu/+spec/larger-livefs

Summary

The live cd file system is currently one big lump which takes a while to generate as well as being inflexible. It should rather be an ordered list of squashfs-es that are mounted on top of each other.

Rationale

The current method of building the live fs makes customising the live cd harder than it needs to. It also means building another live fs for the DVD images (with additional language packs or similar) will take a long time.

Use cases

  • John wants to create a customised live CD. He takes the base livefs and builds a custom squashfs with the packages he wants, then drops that into /casper and burns the whole structure to a CD.

  • Ubuntu wants to have a DVD image with more language packs than would typically fit on a CD. The livefs build process therefore creates a separate squashfs with just the language packs in and makes it available to the DVD build process.

Scope

Affects casper and to a smaller extent the live filesystem and live ISO image building process.

Design and implementation

  • casper will look at /casper/*.squashfs in ASCII order and mount all the squashfs-es there with unionfs. The topmost layer will be a persistent device or just a tmpfs in the same way it currently is.

dsilvers: Would 'run-parts order' be a more useful description than 'ASCII order' ?

tfheen: no, it's in for f in *.squashfs; ... ; done in a C locale order. 


CategorySpec

LiveCDStackedFileSystem (last edited 2008-08-06 16:28:27 by localhost)