CPU, Memory & Disk Space Diagnostics

When a server slows down or runs out of storage, these built-in commands isolate the bottleneck in seconds.

Disk & Inodes

df -h
df -i
du -h --max-depth=1 /var | sort -hr

Memory & Processes

free -h
ps aux --sort=-%mem | head -n 10
vmstat 1 5