Duplicati Backup Guide

Before beginning, ensure you have:

• A RamNode VPS running Ubuntu 20.04 or 22.04 (other distros supported)
• Root or sudo access to your server
• At least 512MB RAM (1GB+ recommended for better performance)
• Storage space for temporary backup data
• A configured backup destination (cloud storage account or remote server)

System Preparation

sudo apt update && sudo apt upgrade -y
sudo apt install wget curl unzip mono-complete mono-devel ca-certificates-mono -y

Duplicati requires Mono to run on Linux. The packages above ensure all necessary runtime components are available.

Download and Install Duplicati

cd /tmp
wget https://updates.duplicati.com/beta/duplicati-latest.deb

# Install the package
sudo dpkg -i duplicati-latest.deb
sudo apt --fix-broken install -y

The --fix-broken command resolves any dependency issues that may arise during installation.

Create a Dedicated User

sudo useradd -r -s /bin/false duplicati
sudo mkdir -p /var/lib/duplicati
sudo chown -R duplicati:duplicati /var/lib/duplicati

Create Systemd Service File

[Unit]
Description=Duplicati Backup Server
After=network.target

[Service]
Type=simple
User=duplicati
Group=duplicati
ExecStart=/usr/bin/duplicati-server --webservice-interface=any --webservice-port=8200 --server-datafolder=/var/lib/duplicati
Restart=on-failure
RestartSec=10
StandardOutput=journal
StandardError=journal

[Install]
WantedBy=multi-user.target

Enable and Start the Service

sudo systemctl daemon-reload
sudo systemctl enable duplicati
sudo systemctl start duplicati
sudo systemctl status duplicati

For production use, it's recommended to place Duplicati behind a reverse proxy with SSL.

Install Nginx and Certbot

sudo apt install nginx certbot python3-certbot-nginx -y

Create Nginx Configuration

server {
    listen 80;
    server_name backup.yourdomain.com;

    location / {
        proxy_pass http://127.0.0.1:8200;
        proxy_set_header Host $host;
        proxy_set_header X-Real-IP $remote_addr;
        proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
        proxy_set_header X-Forwarded-Proto $scheme;

        # WebSocket support
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";

        # Increase timeouts for long backup operations
        proxy_read_timeout 3600s;
        proxy_connect_timeout 3600s;
        proxy_send_timeout 3600s;
    }
}

Enable Site and Get SSL Certificate

sudo ln -s /etc/nginx/sites-available/duplicati /etc/nginx/sites-enabled/
sudo nginx -t
sudo systemctl restart nginx
sudo certbot --nginx -d backup.yourdomain.com

With Reverse Proxy (Recommended)

sudo ufw allow 'Nginx Full'
sudo ufw reload

Direct Access (Without Reverse Proxy)

sudo ufw allow 8200/tcp

Access the Duplicati web interface at:

• With reverse proxy: https://backup.yourdomain.com
• Direct access: http://your-vps-ip:8200

On First Login:

1. Set a strong password: Click "Settings" → "Set password" to protect your backup configuration
2. Configure server settings: Adjust temporary file paths, thread counts, and other performance options
3. Review update settings: Configure automatic update checks

Click "Add backup" and follow the wizard:

1. General Settings

• Name: Descriptive name for your backup
• Encryption: Choose "AES-256 encryption" (strongly recommended)
• Passphrase: Create a strong passphrase (store safely!)

2. Destination Settings - RamNode Object Storage

RamNode provides S3-compatible object storage that integrates seamlessly with Duplicati. First, generate your S3 credentials following our S3 API Quick Start guide.

3. Source Data

Add folders or files to backup and configure exclusion filters for:

• Temporary files: */temp/*, */tmp/*
• Cache directories: */cache/*, */.cache/*
• Log files: *.log
• Database locks: *.lock

4. Schedule & Retention

• Configure backup frequency (e.g., daily at 2 AM)
• Set retention policy to manage old backups
• Example: "Keep all backups from last 7 days, keep weekly for 4 weeks, keep monthly for 12 months"

5. Advanced Options (Recommended)

--blocksize=100kb
--backup-test-samples=10
--keep-time=30D
--retention-policy=1W:1D,4W:1W,12M:1M
--upload-verification-file=true
--auto-vacuum=true

Adjust Thread Counts

• Concurrent uploads: Settings → Advanced → Number of concurrent uploads (Recommended: 4-8 threads)
• Database connections: Settings → Advanced → Number of concurrent database connections (Recommended: 3-5)

Configure Temporary Directory

If your VPS has limited root partition space:

sudo mkdir -p /var/lib/duplicati/temp
sudo chown duplicati:duplicati /var/lib/duplicati/temp

Add to advanced options: --tempdir=/var/lib/duplicati/temp

Email Notifications

Configure SMTP settings in "Settings" → "Default options":

--send-mail-to=admin@example.com
--send-mail-from=duplicati@yourdomain.com
--send-mail-subject="Backup report for %PARSEDRESULT%"
--send-mail-level=Warning,Error

HTTP Reporting (Webhooks)

--send-http-url=https://your-monitoring-service.com/webhook
--send-http-message={"status":"%PARSEDRESULT%","backup":"%backup-name%"}
--send-http-level=Success,Warning,Error

Check Logs

sudo journalctl -u duplicati -f