definition
Jigdo (JIGsaw-DOwnload) can be used to efficiently download daily CD builds or update existing .iso images without the need to re-download the CD image.
installation
The command below will install Jigdo and related files.
sudo apt-get install jigit jigdo jigdo-file
use & example (using Dapper)
The first step in using Jigdo is starting the program using:
jigdo-lite
The program then asks you for the URL to the .jigdo template you want to download.
Jigsaw Download "lite"
Copyright (C) 2001-2004 | jigdo@
Richard Atterer | atterer.net
Getting mirror information from /etc/apt/sources.list
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To resume a half-finished download, enter name of .jigdo file.
To start a new download, enter URL of .jigdo file.
You can also enter several URLs/filenames, separated with spaces,
or enumerate in {}, e.g. `http://server/cd-{1_NONUS,2,3}.jigdo'
jigdo: In this situation we'll use [http://cdimage.ubuntulinux.org/daily/current/dapper-install-i386.jigdo Current Daily Build] (copy link-location & paste into prompt above)
Jigdo will then download a copy of the .jigdo file using wget and then prompt you for any previous images you have to base the download from.
If you already have a previous version of the CD you are downloading, jigdo can re-use files on the old CD that are also present in the new image, and you do not need to download them again. Mount the old CD ROM and enter the path it is mounted under (e.g. `/mnt/cdrom'). Alternatively, just press enter if you want to start downloading the remaining files.
Here you can point Jigdo to an existing .iso file (ie; ~/dapper-install-i386.iso) or a previously burned copy of such (ie; /media/cdrom)
Jigdo then scans the existing files & compares them with the latest copies from the .jigdo template. Result: You only download the differences in the files and not the entire .iso for the latest daily build.