Monitor your VPS and fix common errors

Most VPS problems show up in three numbers: CPU, memory and disk. Learn to read them and the usual errors become quick fixes. Commands target Ubuntu and Debian and may vary elsewhere.

Monitoring commands

• htop shows live CPU, memory and processes (install with sudo apt install htop)
• free -h shows memory and swap
• df -h shows disk usage per mount
• du -sh /var/* | sort -h finds large folders
• uptime shows load averages
• ss -tulpn lists listening ports

Error: SSH connection refused

Something is blocking port 22 or the SSH service is not running.

1. Check the IP and port you are using
2. Use the console or ask support if you cannot log in
3. sudo systemctl status ssh and sudo systemctl start ssh
4. sudo ufw status and confirm SSH is allowed

Error: Permission denied (publickey)

The server wants a key and did not accept yours.

1. Run ssh -v user@IP to see which keys are tried
2. Confirm the right username
3. Check chmod 700 ~/.ssh and chmod 600 ~/.ssh/authorized_keys
4. Make sure the public key is in authorized_keys with no line breaks
5. Use ssh -i path/to/key user@IP for a specific key

Error: No space left on device

1. df -h to find the full mount
2. df -i in case inodes ran out
3. sudo du -xh / --max-depth=1 | sort -h to find the culprit
4. sudo journalctl --vacuum-size=200M to trim logs
5. sudo apt clean and docker system prune if you use Docker

Delete only what you understand.

Problem: High CPU

1. Open htop and sort by CPU with F6
2. Identify the process
3. Restart it with systemctl restart NAME, or stop a runaway one
4. If it returns, check logs with journalctl -u NAME

Unknown processes using all CPU can mean a compromised server, so review logins with last and change credentials.

Prevent trouble

• Set a reminder to check df -h weekly
• Rotate logs
• Add swap for memory spikes
• Upgrade your plan if usage stays high, which you can do any time

If you are stuck, open a ticket on our Discord or email support.