How To Use Jigdo For Incremental CD Updates (Daily Builds)

Last year I wrote a tutorial on the Ubuntu Wiki for using the Jigdo (Jigsaw Download) tool for incremental CD updates. I had forgotten about it until I got into some recent testing for Feisty 7.04. I thought I would revisit my old tutorial and share it with the rest of you. Jigdo is really nice for rebuilding daily CD images without downloading the entire CD again, which can waste bandwidth and time when the latest daily build may have only updated a handful of packages. Here is what you’ll need to setup and use Jigdo.

The first thing you’ll need to do is install the needed jigdo packages.

sudo aptitude install jigit jigdo jigdo-file

It should be noted that Jigdo is a console based application so if you’re afraid of the terminal it might not be the best for you… but I suppose if that were the case you might not be downloading daily builds for testing either.

After the installation finished you’ll want to start Jigdo and you’ll also need a .jigdo file available from the cdimage download page. If you’re interested in the daily builds you can find them here.

Start the application using the command:

jigdo-lite

This will prompt you for a .jigdo URL, as mentioned above. Here is a dump of the initial prompt and message:

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'

You can simply paste in a URL from the above link. This will then dowload the .jigdo file, which is basically a collection of packages and versions included in that image.

After it has an idea of the packages and version numbers that are available in the daily build it’ll prompt you for a current or previous image for comparison. You can supply a mounted CD here if you have one. Here is a dump of the message prompt for the comparison CD.

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.

Jigdo then scans the existing files and compares them with the latest copies from the .jigdo template. This way it is able to find and update only the packages that have been changed since the latest cd image build, cutting down your download time significantly.

You’ve heard me talk about Feisty before and how it is turning out to be a really impressive release. Why don’t you lend a hand, use Jigdo to help test the daily builds and make it absolutely the best release Ubuntu has offered to date!