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

Detecting Hidden Mount Point Overlays

🧩 The Challenge

You suspect a partition or directory mount is hidden because a process wrote files directly to the underlying mount point directory before the filesystem was attached.

💡 The Fix

Use the findmnt command with the pseudo-filesystem check to reveal what is currently obscuring your directory structure.

findmnt --real --submounts --list

⚙️ Why It Works

This command ignores kernel-level virtual filesystems and flattens the output to show the true device-to-mount-point relationships currently active in the kernel namespace.

🚀 Pro-Tip: Pipe the output to grep to search for specific mount points that you suspect are being shadowed by larger filesystem overlays.

Linux Tips & Tricks | © ngelinux.com | 7/9/2026