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?