Justin W wrote: > That brings me to a related question I've wondered for some time: why > do we have to download entire packages for updates? Why can't there be > an RPM package similar to patches? Then you'd only have to download > the difference in a package (and I don't mean a partial file, but just > whole files that have been updates. SuSE has something like this, called patch RPMs or delta RPMs: see ftp://ftp.suse.com/pub/projects/deltarpm/README. Fedora has steered away from the concept to date. Part of the problem with delta RPMs is that they can take up more space and/or more download time: if most of the files have been recompiled against a different version of a library or with a different version of gcc, then one patch RPM could be more than half the size of the full package. If the package is updated again, then you've either got to apply two deltas to get from the original to the newest version (which will be larger than just getting the full RPM), or mirrors[1] have to carry two deltas (original to newest, and update to newest). And the mirror would have to carry the full updated version as well (for people who suddenly want to install the package for the first time), and probably the original package. Alternatively, you could get the mirrors to generate patch RPMs on the fly. But that requires that they run special software just for the Fedora mirror. So far, it's been understood that many mirrors would be reluctant either to see the storage requirement for Fedora increase too drastically, or to run custom software just for Fedora. See also the thread from http://www.redhat.com/archives/rhl-devel-list/2005-March/msg00881.html and http://www.redhat.com/archives/rhl-devel-list/2005-March/msg01031.html. One thing that *has* happened is that Fedora has moved to more, smaller, more independent packages for certain large pieces of software (OpenOffice, X.org), which means that most updates don't involve storing and downloading the whole kit and caboodle just because one file has changed. Hope this helps, James. [1] Places like ftp.kernel.org, which mirror a copy of the Fedora FTP site, providing bandwidth and disk space. -- E-mail: james@ | "The Aldis lamp was developed to flash Morse Code aprilcottage.co.uk | instructions between ships, with the result that one | foggy night in December, a British destroyer found itself | taking orders from the Bismarck's Christmas disco lights, | and set off to attack the YMCA." -- "ISIHAC", BBC R4
