[Bug 589629] Re: LiveCD layout optimisation

[Fitoschido]

Launchpad is not a place for playing around...

** Changed in: baltix
     Assignee: liu bo (1300733887-9) => (unassigned)

** Changed in: debian-cd (Debian)
     Assignee: liu bo (1300733887-9) => (unassigned)

** Changed in: debian-cd (Ubuntu)
     Assignee: liu bo (1300733887-9) => (unassigned)

** Changed in: livecd-rootfs (Ubuntu)
     Assignee: liu bo (1300733887-9) => (unassigned)

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to debian-cd in Ubuntu.
https://bugs.launchpad.net/bugs/589629

Title:
  LiveCD layout optimisation

Status in “debian-cd” package in Ubuntu:
  Fix Released
Status in “livecd-rootfs” package in Ubuntu:
  Fix Released
Status in Baltix GNU/Linux:
  Fix Released
Status in “debian-cd” package in Debian:
  New

Bug description:
  Binary package hint: livecd-rootfs

  As discussed with cjwatson on IRC:

  The Ubuntu Lucid LiveCD stands to have much more locality of reference
  than it currently has. Ideally, the boot files should be bunched
  together on the LiveCD, Linux modules first, then files required by
  boot scripts, then whatever is needed by X to start; icons for
  programs all in one place; and the documentation all in one place as
  well.

  CDs can store more data at the edge (away from the centre) due to CLV
  [1], and need less seeking to access files.

  Seeing as the Ubuntu LiveCD's boot sequence is predictable, based on
  the Filesystem Hierarchy Standard [2], we can make very broad
  assumptions about the need for file access during the boot sequence.

  When the CD starts up, /usr is not read. /bin, /sbin, /lib and
  /lib/modules are used by the startup scripts and Linux loading up. So
  we can place these files together.

  Then X is started, and the rest of the boot scripts. These read files
  from /usr/lib/dri, /etc and /bin, which will be cached (/bin/sh,
  /bin/awk, etc.) Conveniently the files needed by X are all in
  /usr/bin/X11, so we can bunch it with /etc too.

  When the user wants documentation in GNOME, he/she will click links
  leading to other files related to what they want. So put all of these
  files together. But since these files are not often accessed in normal
  use, put them at the *start* of the disc. While /usr/share/doc is not
  *huge*, the documentation will occupy a lot of "radial space" on the
  CD (see attached CD layout image). Then normal use of the CD needs
  much less-wide seeks.

  Sort files using these broad assumptions, for mksquashfs and mkisofs,
  are also attached.

  [1] http://en.wikipedia.org/wiki/Constant_linear_velocity
  [2] http://www.pathname.com/fhs/

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/debian-cd/+bug/589629/+subscriptions