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Ubuntu VPS Initial Setup: Switching from Root to Sudo User

This guide walks through creating a non-root user with sudo privileges, copying SSH keys, testing connection, and disabling direct root logins over SSH.

Quick Reference Summary

Step Task Command
1. Create User Add an unprivileged user adduser <username>
2. Grant Sudo Add user to administrative group usermod -aG sudo <username>
3. Copy SSH Keys Transfer keys from root to new user rsync --archive --chown=<user>:<user> ~/.ssh /home/<user>/
4. Test Access Verify login in a new terminal session ssh <username>@<server_ip>
5. Harden SSH Disable direct root logins PermitRootLogin no in /etc/ssh/sshd_config

Step 1: Create a New User Account

Logged in as root on your fresh VPS, create your new unprivileged user account (replace sammy with your desired username):

adduser sammy

You will be prompted to set and confirm a password. You can press Enter to skip the optional user information fields (Full Name, Room Number, etc.).

Step 2: Grant Administrative Privileges (sudo)

Add the newly created user to the sudo group so you can execute administrative commands when necessary:

usermod -aG sudo sammy

Step 3: Copy SSH Keys to the New User

If you log in using an SSH key pair, you must copy your root user's authorized keys to the new user's home directory.

Option A: Automatic Copy (Recommended)

Run this command while still logged in as root:

rsync --archive --chown=sammy:sammy ~/.ssh /home/sammy/

Option B: Manual Setup

Alternatively, switch to the new user and manually paste your public key:

# Switch to the new user
su - sammy

# Create .ssh directory with correct permissions
mkdir -p ~/.ssh
chmod 700 ~/.ssh

# Paste your public SSH key into authorized_keys
nano ~/.ssh/authorized_keys

# Set strict file permissions
chmod 600 ~/.ssh/authorized_keys
exit

Step 4: Test Your New User Login

⚠️ CRITICAL: Do not close your active root SSH session yet! Keep it open as a fallback in case there is a connection issue.

Open a new terminal window on your local machine and test logging in with your new user account:

ssh sammy@YOUR_VPS_IP

Once connected, test sudo access:

sudo apt update

If prompted, enter your user password. If the package list updates successfully, your user setup is complete and functional.

Step 5: Disable Direct Root Login over SSH

To secure your VPS against brute-force attacks, disable direct root logins.

  1. Open the SSH server configuration file:

    sudo nano /etc/ssh/sshd_config

  2. Locate the line PermitRootLogin and update it to no:

    PermitRootLogin no

  3. Save the file (Ctrl + O, then Enter) and exit nano (Ctrl + X).

  4. Restart the SSH service to apply changes:

    sudo systemctl restart ssh

Post-Setup Verification Checklist

  • Logged in via SSH as non-root user
  • Confirmed sudo privilege execution
  • Direct root SSH login blocked (PermitRootLogin no)
  • Optional: Configured UFW firewall (sudo ufw allow OpenSSH && sudo ufw enable)