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

Find exactly which partition is devouring your SSD space

🧩 The Challenge

Everyone has dealt with that 3:00 AM panic when a partition hits 100 percent usage and the server starts acting like a brick. You run df and see the disk is full, but then you spend forever trying to figure out which nested mount point is actually to blame.

💡 The Fix

Use lsblk to get the big picture of your physical layout combined with a quick du check on specific mounts to pinpoint the heavy hitters. It saves you from digging through mount points that aren’t even on the disk giving you trouble.

lsblk -o NAME,SIZE,MOUNTPOINT,FSTYPE
du -x -h -d 1 / | sort -h

⚙️ Why It Works

Adding the -x flag to du tells it to stay on one filesystem, which is the only way to avoid the headache of accidentally scanning external drives or network mounts. Sorting it numerically makes the space hogs jump straight to the bottom of your screen where they belong.

🚀 Pro-Tip: Alias that du command to something like “dust” so you aren’t hunting for flags when the system is actively dying.

Linux Tips & Tricks | © ngelinux.com | 9/30/2026