Debian Network Reinstall Script

• <span lang="zh-CN">中文版在这里</span>
• <span lang="ja-JP">日本語はこちら</span>

What is this?

A script that reinstalls any VPS or physical machine to minimal Debian via network boot. Works by injecting the Debian installer into GRUB and automatically configuring the installation process.

Perfect for:

• Converting Oracle Cloud's Ubuntu images to Debian
• Removing cloud provider surveillance agents
• Creating minimal, clean Debian environments
• Automating installations with preseed/cloud-init
• Rescuing broken systems

Quick Start

# Download the script
curl -fLO https://raw.githubusercontent.com/bohanyang/debi/master/debi.sh
chmod +x debi.sh

# Basic installation (creates user 'debian' with sudo access)
sudo ./debi.sh

# Or install as root user instead
sudo ./debi.sh --user root

# Reboot when ready
sudo reboot

Default settings: Debian 13 (trixie), DHCP networking, user debian with sudo access, you'll be prompted for password.

Platform Support

| Platform | Status | Notes | |----------|---------|-------| | ✅ KVM/Physical | Full support | All features work | | ✅ Most VPS | Full support | DigitalOcean, Vultr, Linode, etc. | | ⚠️ Google Cloud | Requires manual network | Must use --ip, --gateway (DHCP broken) | | ⚠️ AWS EC2 | BIOS only | UEFI boot not yet supported | | ❌ Containers | Not supported | Requires GRUB bootloader |

Requirements:

• KVM or physical machine (not containers)
• GRUB 2 bootloader
• Root access

Regional Presets

| Preset | Mirror | DNS | NTP | Best for | |--------|---------|-----|-----|----------| | Default | deb.debian.org | Google DNS | time.google.com | Global | | --cloudflare | deb.debian.org | Cloudflare | time.cloudflare.com | Global (privacy) | | --aws | cdn-aws.deb.debian.org | Google DNS | time.aws.com | AWS instances | | --aliyun | mirrors.aliyun.com | AliDNS | time.amazonaws.cn | China | | --ustc | mirrors.ustc.edu.cn | DNSPod | time.amazonaws.cn | China | | --tuna | mirrors.tuna.tsinghua.edu.cn | DNSPod | time.amazonaws.cn | China |

Complete Options Reference

System & User Configuration

| Option | Default | Description | |--------|---------|-------------| | --version 13 | 13 | Debian version: 10, 11, 12, 13, 14 | | --suite trixie | trixie | Debian suite: stable, testing, sid, etc. | | --user debian | debian | Username (use root for root-only) | | --password PASSWORD | prompt | User password (prompted if not specified) | | --authorized-keys-url URL | password auth | SSH keys from URL (e.g., https://github.com/user.keys) | | --no-account-setup | create user | Skip user creation (manual setup via console) | | --sudo-with-password | no password | Require password for sudo commands | | --timezone UTC | UTC | System timezone (e.g., Asia/Shanghai) | | --hostname NAME | current | System hostname |

Network Configuration

| Option | Default | Description | |--------|---------|-------------| | --interface auto | auto | Network interface (e.g., eth0, eth1) | | --ip ADDRESS | DHCP | Static IP: 10.0.0.100, 1.2.3.4/24, 2001:db8::1/64 | | --static-ipv4 | DHCP | Use current IPv4 settings automatically | | --netmask MASK | auto | Network mask: 255.255.255.0, ffff:ffff:ffff:ffff:: | | --gateway ADDRESS | auto | Gateway IP (use none for no gateway) | | --dns '8.8.8.8 8.8.4.4' | 1.1.1.1 1.0.0.1 | DNS servers for IPv4 | | --dns6 '2001:4860:4860::8888' | 2606:4700:4700::1111 | DNS servers for IPv6 | | --ethx | consistent naming | Use eth0/eth1 instead of enp0s3 style | | --ntp time.google.com | time.google.com | NTP server |

Network Console (Remote Installation)

| Option | Default | Description | |--------|---------|-------------| | --network-console | disabled | Enable SSH access during installation |

Network Console Usage:

1. Enable with --network-console and reboot
2. Wait 2-3 minutes for Debian installer to load components
3. SSH to your server: ssh installer@YOUR_IP
4. Use multiple terminals:
   • Alt+F1: Main installer interface
   • Alt+F2: Shell access
   • Alt+F3: Additional shell
   • Alt+F4: System logs (monitor automated installation progress)
   • Navigate with Alt+Left/Alt+Right

[!IMPORTANT]
If --authorized-keys-url is used, SSH password authentication is disabled (SSH keys required), but you still need to set a user password for VNC console and sudo access.

Storage & Partitioning

| Option | Default | Description | |--------|---------|-------------| | --disk /dev/sda | auto-detect | Target disk (required if multiple disks) | | --no-disk-partitioning | auto partition | Manual partitioning via console | | --filesystem ext4 | ext4 | Root filesystem type | | --force-gpt | enabled | Create GPT partition table | | --no-force-gpt | use GPT | Use MBR partition table instead | | --bios | auto-detect | Force BIOS boot (creates BIOS boot partition) | | --efi | auto-detect | Force EFI boot (creates EFI system partition) | | --esp 106 | 106 | EFI system partition size (106=100MB, 538=512MB, 1075=1GB) |

Mirror & Repository Configuration

| Option | Default | Description | |--------|---------|-------------| | --mirror-protocol https | https | Mirror protocol: http, https, ftp | | --https | enabled | Alias for --mirror-protocol https | | --mirror-host deb.debian.org | deb.debian.org | Mirror hostname | | --mirror-directory /debian | /debian | Mirror directory path | | --mirror-proxy URL | none | HTTP proxy for downloads and APT | | --reuse-proxy | none | Use existing http_proxy environment variable | | --security-repository URL | auto | Security updates repo (use mirror for main mirror) |

APT Repository Components

| Option | Default | Description | |--------|---------|-------------| | --apt-non-free-firmware | enabled | Include non-free firmware (Debian 12+) | | --apt-non-free | disabled | Enable non-free repository | | --apt-contrib | disabled | Enable contrib repository | | --apt-src | enabled | Enable source repositories | | --apt-backports | enabled | Enable backports repository | | --no-apt-non-free-firmware | use default | Disable non-free firmware | | --no-apt-non-free | use default | Disable non-free | | --no-apt-contrib | use default | Disable contrib | | --no-apt-src | use default | Disable source repositories | | --no-apt-backports | use default | Disable backports |

Package Installation

| Option | Default | Description | |--------|---------|-------------| | --install 'pkg1 pkg2' | minimal | Additional packages (space-separated, quoted) | | --install-recommends | enabled | Install recommended packages | | --no-install-recommends | install recommends | Skip recommended packages | | --upgrade safe-upgrade | safe-upgrade | Package upgrade mode | | --safe-upgrade | default | Safe package upgrades during install | | --full-upgrade | safe upgrade | Full system upgrade (dist-upgrade) | | --no-upgrade | safe upgrade | Skip package upgrades entirely |

Kernel Options

| Option | Default | Description | |--------|---------|-------------| | --kernel PACKAGE | linux-image-ARCH | Kernel package name | | --cloud-kernel | standard | Use cloud-optimized kernel | | --bpo-kernel | stable | Use newer kernel from backports | | --firmware | auto-detect | Include non-free firmware for hardware |

Advanced Options

| Option | Default | Description | |--------|---------|-------------| | --ssh-port 2222 | 22 | Custom SSH port | | --bbr | disabled | Enable TCP BBR congestion control | | --architecture amd64 | auto-detect | Target architecture: amd64, arm64, i386, etc. | | --force-lowmem 1 | auto | Force low memory mode: 0, 1, 2 (for <512MB RAM) | | --no-force-efi-extra-removable | enabled | Disable EFI extra removable media path | | --grub-timeout 5 | 5 | GRUB menu timeout in seconds |

Debian Installer Options

| Option | Default | Description | |--------|---------|-------------| | --release-d-i | auto | Use release version of debian-installer | | --daily-d-i | auto | Use daily build of debian-installer |

Cloud-Init Integration

| Option | Default | Description | |--------|---------|-------------| | --cidata /path/to/dir | none | Custom cloud-init data directory |

Cloud-Init Usage:

# Create cloud-init configuration
mkdir my-cloud-config
echo "instance-id: my-server" > my-cloud-config/meta-data
cat > my-cloud-config/user-data << 'EOF'
#cloud-config
hostname: my-server
packages:
  - htop
  - git
EOF

# Use with installation
sudo ./debi.sh --cidata my-cloud-config

Development & Testing

| Option | Default | Description | |--------|---------|-------------| | --dry-run | execute | Generate configuration without installing | | --hold | reboot | Don't reboot after installation | | --power-off | reboot | Power off instead of reboot |

Examples

Oracle Cloud (Ubuntu → Debian)

sudo ./debi.sh --cloudflare --user debian

Google Cloud Platform

# GCP requires manual network (replace with your VPC settings)
sudo ./debi.sh --ip 10.128.0.100/24 --gateway 10.128.0.1

Minimal Installation

sudo ./debi.sh --no-install-recommends --install 'curl git vim' --no-upgrade

China Deployment

sudo ./debi.sh --ustc --timezone Asia/Shanghai --dns '119.29.29.29'

Network Console Installation

# Enable remote access during install (SSH keys for network, password still needed for VNC/sudo)
sudo ./debi.sh --network-console --authorized-keys-url https://github.com/yourusername.keys
# After reboot, SSH: ssh installer@YOUR_IP

Static Network with Cloud-Init

sudo ./debi.sh --i