Announcement: update RPMs using delta compression for low bandwidth users

Joe Desbonnet jdesbonnet at gmail.com
Tue Feb 28 18:18:36 UTC 2006


This software is for individual Fedora users and sys-admins who need
to update one or more Fedora systems that are connected to the
internet with low to medium bandwidth link (eg dialup, ISDN,
satellite).

The problem:

Not long after a new Fedora Core release, the bandwidth required to
update a fresh installation can become burdensome for low/medium
bandwidth internet connections. Some update RPMs can be over 80 MBytes
in size, yet the update may be almost identical to the original RPM on
the distribution disk.

This software presents two solutions to administrators of Fedora systems:

1. A HTTP service which acts as a virtual update RPM repository. It
dynamically re-creates
update RPMs by downloading a small 'patch' or 'delta' file and
applying it to locally stored RPMs from the original distribution.

2. A command line tool which can regenerate an update RPM repository
from a delta repository + RPMs from the original distribution.

In addition to the virtual update repository, this software
distribution also contains the tools needed to create and maintain a
delta repository.  I have also made an experimental
delta repository  which is open to testers (subject to sufficient bandwidth).

Requirements and limitations:
* This system uses Michael Schroeder's deltarpm system and must be
installed (documented in the installation instructions)
* Java (tested with the Fedora free stack and Sun Java)
* For the HTTP service you need tomcat5 (the version in the Fedora
distribution will work)
* For delta repository generation you need lots of RAM to process some
of the larger RPMs (eg OpenOffice core).  512MB just about works with
some page faulting, 1024MB+ recommended.

Software version:
0.2.0 (28 Feb 2006)

Binary download:
http://www.wombat.ie/software/rpmdc/downloads/RPMDC-0.2.0-bin.tar.gz

Source download:
http://www.wombat.ie/software/rpmdc/downloads/RPMDC-0.2.0-src.tar.gz

Manual:
http://www.wombat.ie/software/rpmdc/manual.html

Release notes:
http://www.wombat.ie/software/rpmdc/releasenotes-0.2.0.html




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