Linux Disk Usage Commands

Disk issues show up as “no space left” even when space looks fine—check inode exhaustion with df -i. df -h summarizes mount points; du -sh totals directories. lsblk maps block devices to mounts; findmnt shows propagation and options. For deep hunts, combine du with sort or use ncdu when installed.

Command	Shows	Typical flags
df	Filesystem capacity per mount	-h human, -i inodes, -T types
du	Directory usage	-sh summary, -x stay on fs
lsblk	Disks, partitions, mounts	-f filesystems, -o columns

find command, sysadmin commands, process management, sudo

The filesystem may be out of inodes or a quota may apply—check df -i and project quotas.

It skips directories on other filesystems so totals reflect only the target mount.

Run du on top-level paths and sort numerically, or use ncdu for an interactive drill-down.

df reports filesystem-wide free space; du measures usage of directory trees and can disagree with df until unlinked files close.

Open file descriptors keep blocks allocated until processes close—use lsof to find deleted-but-open files.

It lists mount points with options and sources—useful when bind mounts or namespaces hide expected layouts.

When mapping NVMe or LVM devices to mount points before resizing or replacing disks.

Snapshots and subvolumes can share blocks—df and du may need subvolume-aware tools for accurate accounting.

Command	Shows	Typical flags
df	Filesystem capacity per mount	-h human, -i inodes, -T types
du	Directory usage	-sh summary, -x stay on fs
lsblk	Disks, partitions, mounts	-f filesystems, -o columns