Revisit the question of the 700MiB CD limit

Registered by Colin Watson on 2011-05-06

This comes up nearly every cycle, but is worth discussing: revisit whether it is feasible to maintain the 700MiB CD limit on Ubuntu images, or whether we need to shift to a larger image format. Consider:

 * The pressure imposed by new features such as Unity 2D, GTK+ 2/3, the ability to include more language packs, etc.
 * The effect of a less universal format on usability of Ubuntu, especially outside the developed world
 * The discipline imposed by a 700MiB limit, and what limit might be used instead and why
 * Any measures that can be taken to make more space in the existing images
 * Policies that we might impose in future (for example, a "balanced budget" requirement for new features)

Blueprint information

Steve Langasek
Colin Watson
Needs approval
Colin Watson
Series goal:
Accepted for oneiric
Milestone target:
milestone icon oneiric-alpha-3
Started by
Kate Stewart on 2011-08-05
Completed by
Colin Watson on 2012-10-19

Related branches



Work items:
[cjwatson] Convert CD images to hybrid CD/USB images: DONE
[vorlon] Further investigate feasibility of increasing CD limit to 703.125 MiB: DONE
[allison] Prepare USB seeds: DONE
[cjwatson] Switch DVD images over to USB seeds: DONE
[cjwatson] Clarify naming/presentation of new-style DVD images: DONE

[vorlon] indicates that a "700MiB" CD is 360,000 sectors of 2048 bytes each (+error correction). This is 703.125 MiB rather than the 700MiB limit we currently enforce on cdimage.u.c.

pitti, 2011-05-26: Is this missing some WIs to trim down the DVD to a magnitude of 1.5 GB, or has this goal been dropped?

Historical reference for the currently-enforced size limit is:

[rr0hit] Maybe what Fedora guys did with Fedora-15 could be followed. . They achived 19% better compression for the Desktop spin.

[broder] LZMA has been discussed in the past ( but rejected. LZMA is a good enough compression algorithm that it breaks our current ability to do incremental syncs from one daily build to the next, which is necessary for QA.


Work Items

Dependency tree

* Blueprints in grey have been implemented.