Admin Reference

🛠️ Linux Server Administration

Essential tools and practices for running Harmony validator nodes

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Professional validator operation requires solid Linux administration skills. This guide covers the essential tools, security practices, and management techniques needed to run reliable validator infrastructure.

👤 User Account Management

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Never run validators as root! Always create a dedicated service account with sudo privileges for better security and organization.

Creating a Service User

We recommend setting up a dedicated user account with sudo access. In this guide we'll use serviceuser - customize the username to your preference:

adduser serviceuser

Setup Process:

  1. Set a strong password
  2. Skip user info fields (press Enter to leave blank)
  3. Confirm account creation
  4. Add sudo permissions:
sudo usermod -aG sudo serviceuser
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Next Step: Disconnect and reconnect using your new serviceuser account for all future operations.

🔐 SSH Key Authentication

SSH keys provide secure, password-less authentication to your servers. This is essential for professional validator management.

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Important: Re-running key generation with default options will overwrite existing keys. Choose unique filenames if you have multiple key pairs.

🔑 Generate Key Pairs

Run this command on your local computer (not the server):

ssh-keygen -t rsa -b 4096

Parameter Explanation:

  • -t rsa - RSA key type (industry standard)
  • -b 4096 - 4096-bit key length for enhanced security (vs default 3072)

Setup Process:

📁 Key File Overview

FilePurposeSecurity Level
id_rsaPrivate key (keep secure!)🔴 Critical - Never share
id_rsa.pubPublic key (deploy to servers)🟢 Safe to copy
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Backup your private key! Losing id_rsa means losing access to all configured servers.

🚀 Deploy Keys to Server

🔗 Connect Using SSH Keys

Once configured, connect instantly without passwords:

ssh serviceuser@[IP_ADDRESS]
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You're now ready for advanced file transfers using scp, rsync, or tools like Termius for comprehensive server management.

🔒 Security Hardening

Essential security practices for validator nodes exposed to the internet.

🚫 Disable Ping Response

Hide your server from network scans:

# Disable ping responses
sudo sysctl -w net.ipv4.icmp_echo_ignore_all=1
 
# Re-enable ping (if needed)
sudo sysctl -w net.ipv4.icmp_echo_ignore_all=0

🔐 Harden SSH Configuration

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Keep your current SSH session open while making these changes. Test new connections in a separate terminal to avoid lockouts.

Edit SSH configuration:

sudo nano /etc/ssh/sshd_config

Recommended Security Settings:

Apply Changes:

sudo systemctl restart sshd

🔥 Firewall Configuration

Update firewall rules for your new SSH port:

🛡️ Fail2Ban Protection

Automatically ban IPs after failed authentication attempts:

💻 Professional SSH Client

🚀 Termius - Professional SSH Client

Termius (opens in a new tab) is the gold standard for server administration, offering:

  • Multi-device sync - Access servers from any device
  • Built-in SFTP - Drag-and-drop file transfers
  • Snippets - One-click command shortcuts
  • Team collaboration - Share access securely
  • Mobile apps - Manage servers on the go

Get Started:

⚡ Essential Termius Snippets

Configure these one-click shortcuts for validator management:

🔄 Alternative SSH Clients

📁 File Transfer Solutions

🔄 Built-in SFTP (Termius)

Termius includes drag-and-drop file transfer - our recommended solution for most users.

🗂️ Alternative SFTP Clients

🛠️ Essential Linux Tools

Must-have utilities for validator node management:

📊 System Monitoring

🔧 Development Tools

🔄 Maintenance & Updates

🛠️ Validator Toolbox Updates

Harmony & Findora toolboxes auto-update when launched with our recommended snippets. The scripts download the latest version before running.

📦 Ubuntu System Updates

🎯 EasyNodePro Validator Tools

🔧 Harmony Validator Scripts

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Recommendation: Use the Harmony Toolbox instead of individual scripts for better integration and ongoing support.

Legacy Scripts Repository:

🛠️ Findora Validator Scripts

Current Tools Repository:

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You're now equipped with professional server administration skills! These tools and practices form the foundation for reliable validator operations. Remember to practice these techniques in test environments before applying to production validators.

📚 Additional Resources

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