Disk almost full or memory running out

When a disk fills up, databases and websites stop. When memory runs out, the system closes programs to keep going. The panel warns you before this happens if the agent is installed.

On Linux, these commands show what's using the space and memory:

df -h
du -xh / --max-depth=2 2>/dev/null | sort -h | tail -20
journalctl --vacuum-size=200M
free -m
ps aux --sort=-%mem | head