Re: Content of CDs / DVDs
[ Note Reply-To: set to debian-cd; that's the right place for this
Richard Atterer writes:
>On Wed, Oct 20, 2004 at 06:38:07PM -0500, Matthew Dempsky wrote:
>> How difficult is it to generate jigdo templates on the fly? It sounds
>> like a fun project if that's not too difficult a task.
>It's not /that/ easy, because the .template includes a md5 checksum for the
>entire image, and also other, per-file checksums. This means that during
>the on-the-fly generation, all the file data needs to be read into memory
>to calculate the checksum, so creating the .template will take quite a
>(Of course, at the expense of outputting images with a wrong (i.e. zero)
>image md5sum, you can go faster...)
Yes. I was discussing this with some people last night. The MD5 step
is the hard bit. If we are prepared to lose the MD5 of the entire
image (or use another checksum algorithm that can be updated just
using existing checksums of the parts in the image) then we could
probably generate jigdo files on the fly in _seconds_ simply by using
the data already in the Packages files. We'd need to make a few tweaks
to the CD layout, but it's doable if we want it.
>Look at Steve McIntyre's JTE project
><http://www.einval.com/~steve/software/JTE/> for something very much like
>this. As of 2 weeks ago, JTE is used to produce the weekly CD/DVD images.
>All in all, IMHO generating per-user images on the fly is not really
>feasible. However, I think it might make sense to offer several variant CD
>"compilations", a bit like the "Home", "Professional" and "Server" variants
>of other Linux distros.
>OTOH, offering such variants will increase the number of available Debian
>images yet again. We already offer images for different arches, different
>sizes (business-card/netinst/CD/DVD/DLDVD) and different distributions
>(sid/sarge/woody), the total number of images is getting truly confusing,
>especially for people new to Debian.
Steve McIntyre, Cambridge, UK. firstname.lastname@example.org
Welcome my son, welcome to the machine.