Disk & Filesystem Management (Du/Df/Lsblk/Fstrim)

Finding the hidden mount points stealing your capacity

🧩 The Challenge

Ever had a drive look completely empty but you can’t write a single file to it? Usually, there’s a mount point hidden under a directory that’s eating your block device alive.

💡 The Fix

Use findmnt to verify your tree and check for shadowed mount points that aren’t where you expect them to be.

findmnt --real --submounts --target /

⚙️ Why It Works

Running this lists every single mounted filesystem in a clean, hierarchical view so you can spot overlaps instantly. It cuts through the noise of what df or mount usually dump on your screen.

🚀 Pro-Tip: Pipe it to grep if you suspect a specific path is being hijacked by an automounter.

Linux Tips & Tricks | © ngelinux.com | 9/16/2026