Jigdo files for Fedora Core 6

[Jon Burgess]

On Sun, 2006-10-29 at 09:18 -0400, Jesse Keating wrote:
> On Sunday 29 October 2006 01:32, Ian Burrell wrote:
> > I built them using the downloaded core repository instead of from the
> > exploded CD/DVDs. That is why the template files for the disc1 and DVD
> > images are so large.  They contain the complete CD/DVD repodata. I
> > wanted all of the needed files to be downloadable.
> 
> er,that didn't answer the question.  When we compose a release, the repodata 
> is recreated for the CD/DVD, it isn't copied from the os/ dir.  So if you 
> recreate CDs from the exploaded os dir, or an os dir from the CDs, things 
> won't work right.
> 

IMHO it does answer the question once you understand how the template
are composed. They have 2 type of data:-

1) Files which are known to exist (e.g the RPMS), have a pointer saying
that the file should be at a given place in the ISO. This data is then
fetched using the location specified in the .jigdo file when the ISO is
rebuilt.

2) Data which isn't present in the file list (e.g. the repodata) gets
included verbatim in the template file. When the ISO is rebuilt, this
data is copied from the template into the ISO.


The more files that can be fetched remotely to rebuild the ISO, the
smaller the template file can be. Even if all the files are available
then the template will need to contain the ISO9660 filesystem metadata
blocks since these are never present in the downloadable files.


	Jon