Did you try out the Alpha/Beta/RC Versions of Ubuntu, then you don’t need to download the full ISO Image of the latest version(Karmic Koala- 9.10), because you can simply update your existing images to the latest version without the need to re-download the full image using the zsync files available on the ubuntu download server.
Steps to update the Ubuntu ISO Using ZSync :
To get started using zsync you’ll need to run the following command :
sudo aptitude install zsync
Once that is installed you’ll need to rename your existing image, whether it be the alpha, beta or RC image, to that of final image (the one that exists on the server). For example,
mv ubuntu-9.10-rc-desktop-i386.iso ubuntu-9.10-desktop-i386.iso
After you’ve renamed your image to match the final, you can run zsync using the following commands
For the complete list of Mirrors click here.
ZSync compares the existing image files on system with the new files on the server images and download only the new files and recreates the full iso image to the latest version making it easy on the server and also makes it fast to get our hands on the latest version of ubuntu faster.
Incase you dont’t have a Beta/Alpha/RC ISO Image, Download the latest version of Ubuntu (.iso) image.
Via – [ Ubuntu Tutorials ]