The df command

3.1.2.3. The df command

On a running system, information about the partitions can be displayed using the df command (which stands for disk full). In Linux, df is the GNU version, and supports the -h or human readable option which greatly improves readability. Note that commercial UNIX machines commonly have their own versions of df and many other commands. Their behavior is usually the same, though GNU versions of common tools often have more and better features.

The df command only displays information about active non-swap partitions. These can include partitions from other networked systems, like in the example below where the home directories are mounted from a file server on the network, a situation often encountered in corporate environments.

freddy:~>df -h Filesystem          Size  Used Avail Use% Mounted on /dev/hda8           496M  183M  288M  39% / /dev/hda1           124M  8.4M  109M   8% /boot /dev/hda5            19G   15G  2.7G  85% /opt /dev/hda6           7.0G  5.4G  1.2G  81% /usr /dev/hda7           3.7G  2.7G  867M  77% /var fs1:/home           8.9G  3.7G  4.7G  44% /.automount/fs1/root/home

Partitions are mountedon a mount point, which can be almost any directory in the system. In the next section, we'll take a closer look at all those directories.