zsync is a nifty command-line utility that can keep files up-to-date with remote ones.

One of the most popular uses of zync on Ubuntu is for updating Ubuntu’s daily build image with the latest changes – saving the need to download the entire 800MB .iso again.

How It Works

zsync allows you to download a file from a remote server, but by comparing with a local file it will only retrieve the newer parts, thereby minimizing the volume of your download.

Not only does this save time, but is useful for people with download limits on their internet services.

How To:

Once you have zsync installed, one only need visit the Ubuntu daily builds website and copy the .zsync link for the architecture appropriate for your system.

Then in a terminal, simply enter “zsync” plus the URL of the zsync link, for example:

zsync http://cdimage.ubuntu.com/daily-live/current/raring-desktop-amd64.iso.zsync

It’s as simple as that.

If you do not have a copy of the .iso already, don’t worry, zsync will download it automatically (in a rather first-person manner).

zsync automatically downloading the file

Install zsync for Ubuntu

zsync is a free, open-source program and is available to download for Ubuntu via the Software Centre.

Download zsync from the Ubuntu Software Centre 

Or via command line:

sudo apt-get -y install zsync

Or: if Ubuntu’s not your flavour, or for some other reason, the zsync can be downloaded via its official website.

Visit Official Site 

dailybuilds zsync