Hey folks, On Sat, May 21, 2022 at 04:59:27PM +0200, Thomas Schmitt wrote: >Andrew M.A. Cater wrote to debian-cd@lists.debian.org: > >> I don't actually know how long it take to create the .jigdo and .template >> files - I don't think it's as long as generating the full .iso files
Whether you make the .iso or not, we have to run the full process. The *only* part of the process we can win on (a little) is by not actually writing the .iso file to disk. If we don't want the .iso, we output to /dev/null and save a little bit of output I/O [1]. All the same I/O us used for input, of course - we have to scan all the data to generate checksums, etc. >They are created by libjte under control of libisofs under control of >xorriso as side effect of actual ISO production under control of debian-cd. >(I'm developer of libisofs and xorriso, and co-funder of libjte, which is >now back in the hands of Steve McIntyre from whose genisoimage code it >got large parts of its entrails.) > >I was possibly wrong with guessing that the ISO is dumped into /dev/null, >although debian-cd seems to be smart enough to read the various checksums >from the .jigdo files, rather than calculating them from the .iso files. >The checksum code > https://sources.debian.org/src/debian-cd/3.1.35/tools/imagesums/#L57 >reminded me that there are .torrent files made, which obviously need >the .iso files at least at build time. No, youre initial guess is correct. We don't generate the .iso files at all for the larger images [1]. This means we also don't have torrent files for them [2]. There's no point generating the .torrent if we don't have the full .iso available as well, after all. [1] https://salsa.debian.org/images-team/debian-cd/-/blob/master/tools/make_image#L124 [2] https://cdimage.debian.org/cdimage/release/11.3.0/amd64/ >------------------------------------------------------------------------- > >> it's always good to have otehr people to think round a problem with. > >Is there documentation from which i could learn how the stuff in (i guess) >/dists of DLBD-1 and DLBD-2 could be merged so that it properly describes >a merged pool tree ? > >My rough idea would be: >- mount both ISOs >- derive merged /dists files >- run xorriso to let it > - load DLBD-1 with its boot equipment > - merge-in the pool tree of mounted DLBD-2 > - overwrite the old /dists files by the newly derived ones > - automatically replay the commands for the loaded boot equipment > - store the result as new .iso file > >The second step is where i would need info or advise. The debian-cd code in tools/make_disc_trees.pl is not documentation **as such**, but it's exactly how we create disc trees: all the packages/sources and metadata of various flavours. It's baiscally just making a self-contained apt repository on each medium. -- Steve McIntyre, Cambridge, UK. st...@einval.com “Why do people find DNS so difficult? It’s just cache invalidation and naming things.” -– Jeff Waugh (https://twitter.com/jdub)
