Process & Resource Monitoring (Top/Htop/Ps/Systemd)

See which process is eating your I/O for breakfast

🧩 The Challenge

Everything on the box suddenly turns into molasses and htop shows barely any CPU usage. It’s infuriating when you know the drive is thrashing but the usual suspect tools aren’t pointing fingers at the real culprit.

💡 The Fix

Use iotop to track real-time disk activity per process, just like you would with a standard process monitor. It cuts through the noise and lets you see exactly which PID is flooding the disk controller.

sudo iotop -o -a

⚙️ Why It Works

Setting the -o flag hides all the idle threads, and adding -a tracks the accumulated I/O since the command started so you can spot the hidden heavy hitters.

🚀 Pro-Tip: Run it with -P to see processes instead of individual threads if you’re dealing with a massive multi-threaded app.

Linux Tips & Tricks | © ngelinux.com | 9/25/2026