How to create VM templates in Proxmox

Pre-Requisites

Before we could start, we need to make sure, everything is setup correctly. Login into the root shell of the proxmox server. Install the libguestfs-tools to be able to manipulate vm images.

// install the necessary tools on the proxmox host
apt update -y && apt install libguestfs-tools -y

Step 01: Get the Ubuntu image

First we need to download the Ubuntu image and copy it to the proxmox template directory. For convenience we also rename it to ubuntu-base.img. This makes it easier to identify the image later on, even if we have different images later on.

// change to the directory where proxmox keeps the iso images by default
cd /var/lib/vz/template/iso/

wget -P /var/lib/vz/template/iso/ https://cloud-images.ubuntu.com/daily/server/releases/24.04/release/ubuntu-24.04-server-cloudimg-amd64.img

cp ubuntu-24.04-server-cloudimg-amd64.img ubuntu-base.img

Step 02: Massage the image to contain everything

We need to install the qemu-guest-agent to be able to use the cloud init feature of proxmox. We also install the ubuntu-drivers-common package to be able to automatically install the correct drivers for the GPU.

virt-customize -a ubuntu-base.img --install qemu-guest-agent

// sudo apt install ubuntu-drivers-common
virt-customize -a ubuntu-base.img --install ubuntu-drivers-common

// optionally disable ipv6
virt-customize -a ubuntu-base.img --run-command "echo 'net.ipv6.conf.all.disable_ipv6 = 1' >> /etc/sysctl.conf"
virt-customize -a ubuntu-base.img --run-command "echo 'net.ipv6.conf.default.disable_ipv6 = 1' >> /etc/sysctl.conf"
virt-customize -a ubuntu-base.img --run-command "echo 'net.ipv6.conf.lo.disable_ipv6 = 1' >> /etc/sysctl.conf"
virt-customize -a ubuntu-base.img --run-command "sysctl -p"


// remove unique identifier of the image
virt-customize -a ubuntu-base.img --run-command "cloud-init clean --seed --logs --machine-id && truncate -s 0 /etc/machine-id"

Step 03: Create the VM template

qm create 6000 \
  --name "ubuntu-24.04-cloud-init-template" \
  --memory 16384 \
  --cores 4 \
  --cpu host \
  --machine q35 \
  --description "Base ubuntu 24.04 template" \
  --net0 virtio,bridge=vmbr0,tag=42 \
  --agent enabled=1 \
  --ipconfig0 ip=dhcp \
  --tags ubuntu-template,24.04LTS

qm importdisk 6000 /var/lib/vz/template/iso/ubuntu-base.img fastSingle


qm set 6000 --scsihw virtio-scsi-pci \
  --scsi0 fastSingle:vm-6000-disk-0,ssd=1 \
  --boot c \
  --bootdisk scsi0 \
  --ide2 fastSingle:cloudinit \
  --serial0 socket --vga serial0 \
  --bios ovmf \
  --efidisk0 fastSingle:0,efitype=4m,size=4M

qm set 6000 --ciuser ng \
  --cipassword Pass1234 \
  --sshkey /etc/pve/priv/authorized_keys

qm resize 6000 scsi0 +200G

qm template 6000

Step 04: Create an VM from the template

qm clone 6000 200 --name worker-01 --full --storage fastSingle --description "Ubuntu 24.04 cloud image."

References

https://pve.proxmox.com/wiki/Cloud-Init_Support

https://pve.proxmox.com/wiki/Cloud-Init_Support#GPU_passthrough

https://libguestfs.org/