df

The df command is used to examine the available free space on all mounted disk file systems. The -h option is commonly utilized to format the output amounts in KB, MB, GB, and TB. Figure 4.2 shows sample output from the df command.

$\begin{myfigure}[label=fig:4-2]{Using the \tt {df} command} \begin{verbatim}[ali... ... 1% /run/user/1000 tmpfs 397M 0 397M 0% /run/user/0\end{verbatim} \end{myfigure}$

As mentioned previously, the Linux file system is a tree. The df command shows the disk file systems and where they are attached (mounted) on the tree. Each row in the output displays size of the disk file system and how much space is available. The df command includes stats on ‘virtual’ block devices that only exist in RAM. These include the devtmpfs andtmpfs file systems.