Using jigdo to download Ubuntu under Windows

I was recently introduced to jigdo (IMHO the most powerful linux distribution download tool EVAR!). Unlike the traditional method of downloading a huge ISO file in one go, jigdo downloads parts of the CD image and then reassembles them locally in an ISO file. What makes jigdo special, however, is that you can use it to "update" a CD image. In other words, you will only have to download the updated files within the CD to compile an updated CD image, saving you time and precious bandwidth in the process. Jigdo uses wget to download small parts of the CD image. Using the jigdo-lite-settings.txt file, you can pass your own parameters to wget including for example the proxy server address and the number of retries before failing.

Interestingly, jigdo can also be used to circumvent download limits put by network administrators. In some corporate environments, user downloads are limited to relatively small file sizes - preventing the user from downloading whole linux distributions compiled on a single large ISO file. By downloading small parts, jigdo allows that user to circumvent the limit and download the ISO file in small parts.

In our example we will be updating the daily build of Ubuntu Gutsy Gibbon 7.10. Note that jigdo can be used to download a fresh new CD from scratch.

• Grab a copy of jigdo's windows binary from here


• Extract all the files to a separate folder. When you extract the files you will notice that the jigdo-lite-settings.txt file is missing. Start jigdo using the jigdo-lite.bat file. Type any thing at the first prompt, press ENTER and then press CTRL-C and answer Y to terminate the job. Jigdo now created the default jigdo-lite-settings.txt file for you. Open the file with notepad.


• In wgetOpts add (or edit) your own wget parameters. Refer to wget manpage for more info. To add a proxy server add the following parameters:

-e ftp_proxy=http://LOCAL-PROXY:PORT/
-e http_proxy=http://LOCAL-PROXY:PORT/

Where LOCAL-PROXY is the hostname to your proxy server and PORT is the port number. If the proxy requires authentication also add the following parameters:

--proxy-user=USER
--proxy-passwd=PASSWORD

• Now we need to determine the jigdo file for downloading. For the daily build of Ubuntu Gutsy Gibbon the jigdo file URL is http://cdimage.ubuntu.com/daily/current/gutsy-alternate-i386.jigdo .If say we want to download the release version of Ubuntu 7.06 Feisty Fawn the URL is http://releases.ubuntu.com/7.04/ubuntu-7.04-alternate-i386.jigdo


• In the jigdo-lite-settings.txt file change (or add) the URL to the jigdo file to the jigdo= variable. Make sure you surround the URL with a single quote character


• Next we pick a mirror for downloading the file parts. We will use Ubuntu's Germany mirror http://de.archive.ubuntu.com/ubuntu/ because it's the closest to my location. For other mirrors refer to this page.


• In the jigdo-lite-settings.txt file change (or add) the URL to the jigdo mirror to the debianMirror= variable. Make sure you surround the URL with a single quote character like so
debianMirror='http://de.archive.ubuntu.com/ubuntu/'


• If you prefer to keep things organized change the tmpDir= variable to the location of a temporary directory where jigdo can store temporary files.


• Start jigdo by double-clicking the jigdo-lite.bat file!


• jigdo will start by asking for the location of the jigdo file. We already specified that in the jigdo-lite-settings.txt file so we press ENTER. jigdo downloads the jigdo file.


• jigdo will then ask for the location of a previous version of the CD we are downloading. If you have a previous version of the CD enter the path to the old CD ROM's content (e.g. 'D:\'). If you enter the path to the CD, jigdo will compare the files in the CD ROM with the files specified in the jigdo file you specified earlier. It will determine whether to use the mirror or the CD depending on whether the file changed. If, on the other hand, you want to download a fresh copy from scratch just press ENTER.


• jigdo will then ask for the mirror. We already specified that in the jigdo-lite-settings.txt and so we press ENTER. jigdo will now download the .template file and start downloading the CD files one by one. In most circumstances, this will take a very long time so you better leave the Command-Prompt window open and do other things.


• When done downloading jigdo will check the checksum of the newly generated ISO file to make sure everything is in order.


• Burn the ISO file using your favorite CD burning program.


• Enjoy your updated Ubuntu CD!

ps. If you run into any problems refer to jigdo's documentation page