Virtual Machine Templates

Proxmox KVM module WHMCS
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Overview
The module provisions virtual machines by cloning existing Proxmox VM templates. Before using the module, you need to prepare at least one VM template in your Proxmox environment. Templates must be properly prepared inside the Proxmox panel — the module does not install an operating system from ISO, it only clones a ready template and applies configuration via cloud-init.
Physical Requirements
VM templates must meet the following specifications:

Resource sizing: all template parameters (CPU cores, RAM, system disk size) must be smaller than the smallest package you plan to offer clients. The module can grow disks and increase CPU/RAM during deployment, but it cannot shrink them.

Multi-disk layout: if you plan to offer VMs with multiple disks on different storage locations, create those disks on the appropriate storage already in the template. Otherwise Proxmox may consolidate all disks on the same storage during clone.

Cloud-init drive: a cloud-init disk is mandatory for automatic VM configuration after cloning.

Partition layout: partitions of the system disk must be arranged so that the root partition is the LAST partition in the table. This is required for automatic root filesystem expansion by cloud-initramfs-growroot during first boot.

Cloud-Init Requirement
Cloud-init is required for automatic VM configuration. The module uses cloud-init to set:

Hostname
IP address and network configuration
DNS servers
User account and password
SSH keys

Without cloud-init, the module cannot automatically configure the VM's network and credentials after cloning.
Creating a Template
Step 1: Create a Base VM
Create a new VM in Proxmox with your desired operating system. When partitioning the system disk, ensure the root partition is the LAST one in the partition table so that it can be automatically expanded on first boot.
Step 2: Enable Root SSH Access
The module uses the root user to push cloud-init configuration and manage the VM. Enable root login via SSH inside the template:
# /etc/ssh/sshd_config
PermitRootLogin yes
PasswordAuthentication yes

systemctl restart sshd

Step 3: Install Cloud-Init
Install cloud-init together with the growroot and utility packages inside the VM:
# Debian/Ubuntu
apt update && apt install -y cloud-initramfs-growroot cloud-init cloud-utils

# CentOS/RHEL/AlmaLinux
yum install -y cloud-init cloud-utils-growpart

# openSUSE
zypper install cloud-init growpart

cloud-initramfs-growroot / cloud-utils-growpart is what actually expands the root partition to fill the resized disk during deployment. Without it the client VM will boot with the original template disk size.

Step 4: Enable Cloud-Init Services
Cloud-init is split into four systemd services — all of them must be enabled so the VM picks up configuration on every boot:
systemctl enable cloud-init-local.service
systemctl enable cloud-init.service
systemctl enable cloud-config.service
systemctl enable cloud-final.service

Step 5: Clean Up the VM
Before converting to a template, clean up the VM so that every clone starts fresh:
# Remove default users created during OS install (ubuntu, debian, centos, etc.)
# The module creates the user defined in the product configuration.
userdel -r ubuntu 2>/dev/null || true
userdel -r debian 2>/dev/null || true

# Remove SSH host keys (they will be regenerated on first boot)
rm -f /etc/ssh/ssh_host_*

# Clean cloud-init state
cloud-init clean --logs

# Remove machine ID (will be regenerated)
truncate -s 0 /etc/machine-id
rm -f /var/lib/dbus/machine-id
ln -s /etc/machine-id /var/lib/dbus/machine-id

# Clear logs
find /var/log -type f -exec truncate -s 0 {} \;

# Clear bash history
cat /dev/null > ~/.bash_history && history -c

Step 6: Add Cloud-Init Drive
In the Proxmox web UI:

Select the VM
Go to Hardware

Click Add > CloudInit Drive

Select the storage for the cloud-init drive

Step 7: Convert to Template
In the Proxmox web UI:

Right-click the VM
Select Convert to Template

Template Configuration Tips

Use a unique VMID for each template to avoid conflicts

Keep templates on shared storage if you have a multi-node cluster, or use local storage with migration enabled in the module settings

Install the QEMU Guest Agent (qemu-guest-agent package) for improved VM management and status reporting

Configure serial console if you want noVNC console access to work properly

Minimize the template disk size — the module can resize disks during deployment, but it cannot shrink them

Test the template by manually cloning it and verifying that cloud-init applies the configuration correctly

Pre-built Templates
If you don't want to build templates from scratch, PUQcloud publishes two separate sets of ready-made VM templates as Proxmox backup archives (VMA format, .vma.zst):

Prebuild Proxmox OS templates — custom minimal installations built by PUQcloud from scratch.

Official cloud images with root access — upstream cloud images (Debian Cloud, Ubuntu Cloud, CentOS GenericCloud) modified so that root SSH login works out of the box.

Both sets are hosted under the same root folder:

https://files.puqcloud.com/Proxmox_OS_Templates/

Download Prebuild Proxmox OS Templates
Custom PUQcloud builds — 5 GB virtio disk, no swap, minimal install, root SSH enabled, default password puqcloud, timezone Europe/Warsaw.
Debian

Debian 10

Debian 11

Debian 12

Ubuntu

Ubuntu 18

Ubuntu 20

Ubuntu 22

CentOS

CentOS 7

CentOS 8

CentOS 9

Proxmox

PBS 2.2

Official Cloud Images with Root Access
These are the upstream cloud images from Debian, Ubuntu and CentOS, modified by PUQcloud so that root SSH login is enabled out of the box. Use them if you prefer the official distribution builds over custom ones.

Stock upstream cloud images disable root SSH login by default and create a non-root user (debian, ubuntu, centos). The module requires the root account to push cloud-init configuration and run management commands — that's why the "with root access" variants exist.

Debian

Debian 10 — ~245 MB

Debian 11 — ~275 MB

Debian 12 — ~298 MB

Debian 13 — ~307 MB

Ubuntu

Ubuntu 20.04 — ~893 MB

Ubuntu 22.04 — ~626 MB

Ubuntu 23.10 — ~731 MB

CentOS

CentOS 7 — ~1.01 GB

CentOS 9 — ~1.10 GB

File names may change over time. If a direct link returns 404, open the parent folder on files.puqcloud.com and grab the latest archive for the OS version you need.

Importing a Pre-built Template

Copy the .vma.zst file to your Proxmox node, for example into /var/lib/vz/dump/:
cd /var/lib/vz/dump/
wget https://files.puqcloud.com/Proxmox_OS_Templates/Debian/Debian-12/vzdump-qemu-1012-2024_03_23-17_11_11.vma.zst

Restore the backup to a new VMID (pick a free ID, e.g. 9012) and target storage (e.g. local-lvm):
qmrestore /var/lib/vz/dump/vzdump-qemu-1012-2024_03_23-17_11_11.vma.zst 9012 --storage local-lvm

Alternatively, use the Proxmox web UI: Datacenter > Storage > Backups > Restore.
Open the restored VM, change the default root password (puqcloud for the prebuild set), verify the cloud-init drive is present, then right-click the VM and choose Convert to Template.

Disclaimer: Your use of these operating systems is at your own risk. PUQcloud does not guarantee the correct operation or security of the pre-built templates or the root-access cloud images. Always review, update and harden them before offering to clients.

Supported Operating Systems
The module supports any operating system that Proxmox can run as a KVM virtual machine, provided it has working cloud-init (or cloudbase-init on Windows). Tested and known to work:

Linux: Debian, Ubuntu, CentOS, AlmaLinux, Rocky Linux, openSUSE, Proxmox Backup Server

Windows: Server / Desktop editions with cloudbase-init installed

Configuring Templates in WHMCS
Templates are selected in the product configuration under the Module Settings tab. You can also offer multiple templates to clients via Configurable Options, allowing them to choose their preferred operating system during order.