5 Essential Linux Commands to Monitor Disk Space and Free Up Storage

df command

The df (disk‑free) command shows used and available disk space on a Linux system. Common options include: df -h: display sizes in a human‑readable format (e.g., MB, GB) instead of raw bytes. df -a: include all filesystems, even those with zero blocks. df -T: show the filesystem type for each mount point (e.g., ext4, xfs, btrfs). df -i: display inode usage (used and free inodes).

If you prefer a graphical interface, the GNOME Disks utility (gnome‑disk‑utility) can display the same information.

du command

The du (disk usage) command reports the size of files and directories, defaulting to kilobytes. Useful options are: du -h: human‑readable output for all directories and sub‑directories. du -a: include every file in the size report. du -s: show only the total size for each argument.

Graphical alternatives include GNOME’s Disk Usage and KDE’s Filelight, which visualize usage as concentric rings.

ls -al command

The familiar ls command, with the -al flags, lists all entries in a directory, showing permissions, owners, sizes, and timestamps.

stat command

The stat command takes a file or directory as an argument and displays detailed statistics, including size, inode number, permissions, and timestamps.

fdisk -l command

The fdisk -l command lists disk sizes and partition tables, useful for understanding the layout of storage devices.

All of these commands are built‑in to Linux and require no extra installation. Third‑party tools such as Disks and Ncdu provide visual representations of disk usage for those who prefer a GUI.