Debian 13 (Trixie) → Proxmox VE 9 – Simplified Installation on Pure Debian

Proxmox VE 9 is based on Debian 13 (Trixie) and introduces a newer kernel, updated LXC, QEMU and improved virtualization stack. This guide presents a simplified and automated method to install Proxmox VE 9 on a clean Debian 13 system using two installation scripts.

The method follows the same approach as my previous Proxmox 8 on Debian 12 guide, but adapted for Debian 13 and Proxmox VE 9.

Prerequisites

  • Fresh Debian 13 (Trixie) installation
  • Root access
  • Internet connectivity

All commands must be executed as root.

Part 1 – System Preparation & Proxmox Kernel Installation

Download the first script:

This script:

  • Sets hostname and updates /etc/hosts
  • Installs Proxmox archive keyring (verified via SHA512)
  • Adds Proxmox VE 9 repository for Debian 13
  • Performs full system upgrade
  • Installs proxmox-default-kernel
  • Reboots the system

Content of install-proxmox9-part1.sh

Part 2 – Proxmox VE 9 Installation

After reboot, download and execute:

Content of install-proxmox9-part2.sh

Accessing the Web Interface

After completing the second script, open:

Login with the root user and your root password. You may see a certificate warning — this is normal for fresh installations.

Troubleshooting – 401 Unauthorized (pve-enterprise repository)

If after installation or during apt update you encounter the following error:

This means the enterprise repository is enabled but your system does not have a valid Proxmox subscription. If you are using the no-subscription repository (as shown in this guide), you should disable the enterprise repository.

Fix it by running:

After this, the update should complete successfully:

If everything is correct, you should see:

Conclusion

This method provides a clean and controlled way to deploy Proxmox VE 9 directly on Debian 13 without using the ISO installer. It is especially useful for automated environments, labs, and custom infrastructure setups.