The ubuntu 9.10 beta iso images for various architectures are shipped along with zsync files for easy update of iso images from previous releases. This post will show how you can use zsync to save your bandwidth and time while you download the next version of the karmic koala.
zsync is a file transfer program similar to rsync. zsync is optimized for distribution of files across Internet, with one file on a server to be distributed to thousands of down loaders.
Recently ,I used zsync to update the iso image of karmic koala alpha6 to beta . This is what I did on my ubuntu Jaunty machine.
$ sudo apt-get install zsync
I had downloaded the alpha version of karmic koala and kept it as karmic-desktop-i386.iso in my home folder. For updating this image to the beta release I typed the following command.
$ zsync -i karmic-desktop-i386.iso http://releases.ubuntu.com/karmic/ubuntu-9.10-beta-desktop-i386.iso.zsync
The above command will read karmic-desktop-i386.iso from my hard disk and compare it with the ubuntu-9.10-beta-desktop-i386.iso on the ubuntu servers and update the local image to new version.
As per the release schedule for karmic, the release candidate and final release are expected on 22nd and 29th of October 2009. Get ready with zsync for updating your beta iso to the final .
( Ubuntu provides jigdo files which can also be used to update the image)