what is the difference between available and free disk space? see image below: http://alvarberglind.se/disk.png
On an EXT file system, a proportion of the free space is reserved for root usage, as the system needs some of this free space to run properly. The available space is the Free space, less this reserved amount.
You can change the amount of reserved space when you create the filesystem with the
You can change the reservation on an existing filesystem using
In both cases, the argument to