Q:

Mount error: "unknown filesystem type 'exfat'"

When trying to mount an exfat filesystem, I get the following error:
Error mounting /dev/sda6 at /media/gkp/Backup: Command-line 
`mount -t "exfat" -o "uhelper=udisks2,nodev,nosuid" "/dev/sda6" "/media/gkp/Backup"' 
exited with non-zero exit status 32: mount: unknown filesystem type 'exfat'

Exfat is used on some USB sticks and camera sd cards.  What can I do to mount this type of filesystem? 

A:

You get this error because the exfat filesystem is not installed in Ubuntu by default.  exFAT is proprietary and patented by Microsoft.  
Ubuntu 13.10 or higher
Since Ubuntu 13.10, this package is in the main repository.  Just install exfat-fuse and exfat-utils:
sudo apt-get install exfat-fuse exfat-utils

Ubuntu 12.04
For ubuntu 13.04 and lower, you'll need a ppa to install the exfat support.  Installation procedure: 
sudo apt-add-repository ppa:relan/exfat
sudo apt-get update
sudo apt-get install fuse-exfat

If you see the error gpg: "tag:launchpad.net:2008:redacted" not a key ID: skipping during the apt-add-repository step, then you'll need to manually install the signing key and run the apt-get update and apt-get install steps after that:
sudo apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 4DF9B28CA252A784

​​​​​​

