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

Track down why a process is hogging the disk before you kill the wrong thing

🧩 The Challenge

Dealing with a server that suddenly grinds to a halt because some mystery process is chewing through I/O, but top shows barely any CPU usage. It’s infuriating when the system is responsive enough to login but too sluggish to run basic commands.

💡 The Fix

Use iotop to watch what is actually hitting the disk in real time so you can identify the culprit by PID or user. You’ll stop guessing if it’s a runaway log rotate or a database backup gone rogue.

sudo iotop -o -P

⚙️ Why It Works

Setting the -o flag filters the list to show only processes performing I/O, while -P ensures you see the actual process rather than individual threads, making the output way easier to parse during a firefight.

🚀 Pro-Tip: Pipe the output to grep if you suspect a specific user is causing the mess.

Linux Tips & Tricks | © ngelinux.com | 9/20/2026