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

Stop mount points from masking your actual disk data

🧩 The Challenge

You ever mount a new drive to a folder that already had files in it, only to realize later you’ve completely orphaned your old data? I spent three hours hunting for logs that I swore were on the root partition, but they were sitting invisible underneath a mount point.

💡 The Fix

Use findmnt to verify your mount tree before you start pushing data into what looks like an empty directory. It saves you from accidentally writing to the underlying partition instead of the mounted disk.

findmnt --real --target /your/mount/path

⚙️ Why It Works

This utility walks the kernel mount table and shows you exactly what is sitting on top of that path, cutting through the confusion of what you see in a standard ls output. It avoids the guesswork because it queries the kernel state directly rather than relying on directory listings.

🚀 Pro-Tip: Run mount –bind /tmp/something /real/data/path to move files out from under a mount without a reboot.

Linux Tips & Tricks | © ngelinux.com | 7/30/2026