One of the most common error one faces while updating Ubuntu, either through Software Updater or in Terminal, is “Failed to download repository information Check your Internet connection.”
However, this is a generic error shown for any kind of Ubuntu update error. What you need to know is exactly what’s wrong with it. And for that, you’ll have to use the terminal.
Open the terminal application and use the following command:
sudo apt-get update
There will be a huge output. Don’t worry about that. Once the command finishes running, carefully look at the last two or three lines. This is where you’ll find the exact error.
W:Failed to fetch bzip2:/var/lib/apt/lists/partial/in.archive.ubuntu.com_ubuntu_dists_oneiric_restricted_binary-i386_Packages Hash Sum mismatch W:Failed to fetch bzip2:/var/lib/apt/lists/partial/in.archive.ubuntu.com_ubuntu_dists_oneiric_multiverse_binary-i386_Packages Hash Sum mismatch E:Some index files failed to download. They have been ignored, or old ones used instead
As you can see, the error is “Hash Sum Mismatch”. If you don’t see this error, try this tutorial to fix ‘failed to download repository information‘ error.
The one shot solution to this problem which has always worked for me is to run the following commands in terminal:
sudo rm -rf /var/lib/apt/lists/* sudo apt-get update
I hope this quick tip helps you as well.