Ubuntu VM

https://ubuntu.com/server

Installation

There are multiple methods to install the OS.

Cloud Image with Cloud-init (Recommended)

This is the recommended method for fully automated VM creation with zero manual interaction.

How it works:

• Downloads pre-installed Ubuntu cloud image (~700MB vs ~2.5GB ISO)
• Imports the image directly as a VM disk (no installer needed)
• Cloud-init configures hostname, users, SSH keys, and packages on first boot
• VM boots directly to a configured state in ~30-60 seconds

Quickstart:

• Setup SSH access to the PVE host
• Edit create-ubuntu-cloud-vm.sh to match the desired configuration
• Execute to deploy an Ubuntu Server VM:

ssh root@proxmox "bash -s" -- < create-ubuntu-cloud-vm.sh

• Start the VM - it will boot directly to a ready-to-use system

Verify cloud-init status:

ssh buba@<vm-ip> "cloud-init status --wait"

Limitations:

• Uses default disk layout (cannot customize partitions/LVM like autoinstall)
• If you need custom storage layout, use the autoinstall method below

References:

• Proxmox - Cloud-Init Support
• Ubuntu Cloud Images
• Cloud-init Documentation

Automatic install - “autoinstall”

Use this method when you need custom storage layouts (LVM, partitions, RAID).

Note: This method still requires a manual confirmation at the VM console (“Continue with autoinstall?” prompt) unless you modify the installation ISO to include the autoinstall kernel parameter.

Quickstart:

• Setup SSH access to the PVE host
• Edit create-ubuntu-server-vm.sh to match the desired configuration
• Execute to deploy an Ubuntu Server VM:

ssh root@proxmox "bash -s" -- < create-ubuntu-server-vm.sh

• Start the VM and confirm the installation (“Continue with autoinstall?” prompt)

Details:

Introduction to autoinstall

Automatic Ubuntu installation is performed with the autoinstall format. You might also know this feature as “unattended”, “hands-off” or “preseeded” installation. Automatic installation lets you answer all configuration questions ahead of time with an autoinstall configuration and lets the installation process run without any interaction.

Good guides describing autoinstall’s possibilities:

• How to write and perform Ubuntu unattended installations with autoinstall
• How to automate a bare metal Ubuntu 22.04 LTS installation

Notes:

When any Ubuntu system is installed (manual or automated) an autoinstall file for repeating the installation is created at /var/log/installer/autoinstall-user-data.

Even if a fully non-interactive autoinstall config is found, the server installer will ask for confirmation before writing to the disks unless “autoinstall” is present on the kernel command line. This is to make it harder to accidentally create a USB stick that will reformat a machine it is plugged into at boot. (source)

To achieve fully unattended autoinstall, you would need to modify the installation ISO’s GRUB configuration to include the autoinstall kernel parameter.

Manual install

This method creates a VM, downloads the installation media and attaches it for manual installation.

• Setup SSH access to the PVE host
• Edit create-ubuntu-server-vm.sh to match the desired configuration and set: AUTOINSTALL=false
• Execute to deploy an Ubuntu Server VM:

ssh root@proxmox "bash -s" -- < create-ubuntu-server-vm.sh

• Start the VM and use the installer

Method Comparison