Introduction

VM templates in Proxmox provide a powerful way to standardize and accelerate virtual machine deployments. Instead of manually configuring each new VM from scratch, you can create a template once and clone it as many times as needed, ensuring consistency across your infrastructure.

Common use cases for VM templates:

  • Rapid deployment of multiple identical servers
  • Testing environments that need to be quickly provisioned and destroyed
  • CI/CD pipeline workers that require consistent configurations
  • Development environments for team members
  • Staging environments that mirror production

A template is essentially a read-only VM configuration that serves as a blueprint. Once converted to a template, the VM cannot be started or modified directly, ensuring the template remains pristine for cloning operations.

Prerequisites

Before creating a VM template, ensure you have:

  • Proxmox VE installed and accessible (tested with 6.x, 7.x, 8.x)
  • An existing VM that you want to convert to a template
  • Administrative access to the Proxmox web interface
  • Basic familiarity with Proxmox VM management

Recommended before templating:

  • Remove machine-specific data (SSH host keys, logs, temporary files)
  • Update the OS and install common software packages
  • Configure cloud-init if planning to automate deployments
  • Test the VM thoroughly to ensure it works as expected

Part 1: Prepare the Source VM

Before converting a VM to a template, it’s important to prepare it properly to ensure clean clones.

1. Clean Up the Source VM

SSH into the VM and remove machine-specific data:

# Remove SSH host keys (regenerated on first boot of clone)
sudo rm -f /etc/ssh/ssh_host_*

# Clear machine ID
sudo truncate -s 0 /etc/machine-id

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

# Remove temporary files
sudo rm -rf /tmp/*
sudo rm -rf /var/tmp/*

# Clear logs (optional but recommended)
sudo truncate -s 0 /var/log/wtmp
sudo truncate -s 0 /var/log/btmp
sudo find /var/log -type f -name "*.log" -exec truncate -s 0 {} \;

2. Update and Configure Software

# Update all packages to latest versions
sudo apt update && sudo apt upgrade -y

# Install commonly needed tools
sudo apt install -y qemu-guest-agent cloud-init

# Enable QEMU guest agent (allows Proxmox to query VM info)
sudo systemctl enable qemu-guest-agent
sudo systemctl start qemu-guest-agent

3. Shutdown the VM

Once preparation is complete, shut down the VM cleanly:

sudo shutdown -h now

Or from the Proxmox shell:

qm shutdown <vmid>

⚠️ Important: Never convert a running VM to a template. Always shut down first to avoid corruption.

Part 2: Create the Template

Now that the VM is prepared and shut down, you can create a template using the Proxmox web interface or command line.

  1. Log into Proxmox web interface (https://your-proxmox-ip:8006)

  2. Navigate to the VM you want to convert in the left sidebar

  3. Verify VM is stopped - Status should show “stopped”

  4. Right-click the VM and select Convert to Template

  1. Confirm the conversion - Click “Yes” in the confirmation dialog

  2. Verify template creation - The VM icon will change to a template icon (looks like a document)

Note: This operation is irreversible via the GUI. The VM is now a template and cannot be started directly.

Method B: Using Proxmox Command Line

SSH into the Proxmox host and run:

# Convert VM with ID 9000 to template
qm template 9000

Example output:

Converted VM 9000 to template

Part 3: Clone the Template

Now that you have a template, you can create new VMs by cloning it.

Using Proxmox Web Interface

  1. Right-click the template in the sidebar

  2. Select Clone

  1. Configure clone settings:

    • Target Node: Select which Proxmox node to create the clone on
    • VM ID: Assign a unique ID (e.g., 101, 102, 103)
    • Name: Enter a descriptive name (e.g., web-server-01)
    • Mode: Choose clone type:
      • Full Clone: Independent copy (recommended for production)
      • Linked Clone: Depends on template (faster, uses less space, good for testing)
    • Target Storage: Select where to store the new VM’s disk

  2. Click Clone to create the new VM

  3. Start the cloned VM - The new VM can now be started and configured

Using Command Line

# Full clone from template 9000 to new VM 101
qm clone 9000 101 --name web-server-01 --full

# Linked clone (faster, smaller)
qm clone 9000 102 --name test-server-01

# Clone to specific storage
qm clone 9000 103 --name db-server-01 --full --storage local-lvm

Expected output:

create full clone of drive scsi0 (local-lvm:vm-9000-disk-0)
Formatting '/var/lib/vz/images/101/vm-101-disk-0.qcow2', fmt=qcow2 size=34359738368
transferred: 0 bytes remaining: 34359738368 bytes total: 34359738368 bytes progression: 0.00 %
...
transferred: 34359738368 bytes remaining: 0 bytes total: 34359738368 bytes progression: 100.00 %

Part 4: Post-Clone Configuration

After cloning, you’ll need to customize the new VM to make it unique.

1. Start the Cloned VM

# From Proxmox shell
qm start 101

# Or use the GUI: Select VM -> Start button

2. Regenerate Machine-Specific Data

SSH into the new VM and regenerate SSH host keys:

# Regenerate SSH host keys
sudo dpkg-reconfigure openssh-server

# Generate new machine ID
sudo systemd-machine-id-setup

# Verify new machine ID was created
cat /etc/machine-id

3. Configure Network Settings

If using static IPs (recommended for servers):

# Edit netplan configuration
sudo nano /etc/netplan/00-installer-config.yaml

Example static IP configuration:

network:
  version: 2
  ethernets:
    ens18:
      addresses:
        - 192.168.1.101/24
      routes:
        - to: default
          via: 192.168.1.1
      nameservers:
        addresses:
          - 8.8.8.8
          - 8.8.4.4

Apply the configuration:

sudo netplan apply

4. Update Hostname

# Set new hostname
sudo hostnamectl set-hostname web-server-01

# Update /etc/hosts
sudo nano /etc/hosts
# Change old hostname to new one

Converting a Template Back to a VM

If you need to modify a template, you must first convert it back to a regular VM.

⚠️ Warning: This is irreversible via GUI. Consider cloning the template instead of converting it.

Using Command Line Only

# Convert template 9000 back to a regular VM
qm set 9000 --template 0

Better approach: Clone the template, modify the clone, then create a new template:

# Clone template to temporary VM
qm clone 9000 999 --name temp-template-update --full

# Start and modify VM 999
qm start 999
# Make your changes via SSH...

# Shutdown and convert to new template
qm shutdown 999
qm template 999

# Delete old template (optional)
qm destroy 9000

Best Practices

Template Organization

Naming Convention:

  • Use descriptive names: ubuntu-22.04-template, debian-12-minimal-template
  • Include OS version and purpose: rocky-9-webserver-template
  • Add date for versioning: ubuntu-22.04-template-2024-12

Storage Considerations:

  • Store templates on fast, redundant storage
  • Use SSD storage for templates that will be cloned frequently
  • Keep templates small (remove unnecessary packages and data)

Template Maintenance

Regular Updates:

# Quarterly update workflow
# 1. Clone template to temporary VM
qm clone 9000 999 --name template-update --full
qm start 999

# 2. SSH in and update packages
ssh user@temp-vm
sudo apt update && sudo apt dist-upgrade -y

# 3. Clean up and shutdown
# (run cleanup commands from Part 1)
sudo shutdown -h now

# 4. Create new template version
qm template 999

# 5. Test the new template by cloning it
qm clone 999 1000 --name test-clone --full
# Test thoroughly...

# 6. Rename for version tracking
qm set 999 --name ubuntu-22.04-template-2024-12

Multiple Template Strategy

Create specialized templates for different use cases:

  • Minimal Template: Basic OS only (fastest to clone)
  • Web Server Template: OS + Nginx/Apache + common tools
  • Database Template: OS + PostgreSQL/MySQL + backup tools
  • Development Template: OS + dev tools + IDE + compilers

Example template inventory:

9000: ubuntu-22.04-minimal-template
9001: ubuntu-22.04-webserver-template
9002: ubuntu-22.04-database-template
9003: debian-12-docker-template

Troubleshooting

Template Won’t Clone

Symptoms:

Error: storage 'local-lvm' does not support snapshots

Solution: Use full clone instead of linked clone

qm clone 9000 101 --full

Cloned VM Has Same IP/Hostname

Cause: Network configuration not updated after cloning

Solution: Update network config and hostname (see Part 4)

Template Uses Too Much Space

Solution: Clean up unnecessary files before templating

# Remove package cache
sudo apt clean

# Remove old kernels
sudo apt autoremove --purge

# Clear systemd journal
sudo journalctl --vacuum-time=1d

Can’t Start Template

Cause: Templates cannot be started directly (this is by design)

Solution: Clone the template first, then start the clone

Next Steps

Now that you have a working template, you can:

  1. Automate cloning with Terraform (see related post: “How to Automate Proxmox with Terraform”)
  2. Configure cloud-init for automatic VM customization (see related post: “How to Create a Cloud-Init Template”)
  3. Create multiple templates for different server types
  4. Set up a template update schedule to keep templates current
  • How to Automate Proxmox VM Creation with Terraform
  • How to Create a Cloud-Init Template VM in Proxmox
  • How to Resize an Ubuntu VM Disk in Proxmox

Last updated: November 2025