ISO VM templates

It is important to set up a template for VMs due to the long process it can take but the value in isolation instead of just linux containers.

1. Update and Upgrade Packages:

   • First, ensure all packages are up-to-date. This step is optional but recommended.

     <syntaxhighlight lang="bash">sudo apt update && sudo apt upgrade -y</syntaxhighlight>

2. Clean Up APT Cache:

   • Remove downloaded package files to save space.

     <syntaxhighlight lang="bash">sudo apt clean</syntaxhighlight>

3. Remove Old Kernels (optional):

   • This step is optional and only needed if you’ve upgraded the kernel and have old ones lying around.

     <syntaxhighlight lang="bash">sudo apt autoremove --purge</syntaxhighlight>

4. Clear Temporary Files and Directories:

   • Clear out temporary files to clean up the system.

     <syntaxhighlight lang="bash">sudo rm -rf /tmp/ /var/tmp/</syntaxhighlight>

5. Clear System Logs:

   • Clearing old logs can help protect privacy and reduce template size.

     <syntaxhighlight lang="bash">sudo find /var/log -type f -exec truncate -s 0 {} \;</syntaxhighlight>

6. Clear Bash History:

   • Clear the command history to remove any traces of commands you’ve run.

     <syntaxhighlight lang="bash">history -c && history -w</syntaxhighlight>

7. Reset Network Settings (if necessary):

   • If you want the cloned VMs to configure network settings on first boot, reset the network configuration. This process depends on whether your VM uses ifupdown, NetworkManager, or systemd-networkd.

   For ifupdown, edit /etc/network/interfaces and remove or comment out all configurations except lo (loopback).

8. Generalize the System (optional for Linux):

   • Unlike Windows, Linux doesn’t require a generalize step like sysprep. However, you might want to remove or anonymize machine-specific data, such as SSH host keys (they will regenerate on first boot).

     <syntaxhighlight lang="bash">sudo rm -f /etc/ssh/ssh_host_*</syntaxhighlight>

9. Shutdown the VM:

   • Once you’ve completed these steps, shut down the VM.

     <syntaxhighlight lang="bash">sudo shutdown now</syntaxhighlight>

After the VM is shut down, you can convert it into a template in Proxmox. This template can then be used to deploy new VMs quickly. Remember, each cloned VM will require some initial setup, such as setting hostnames and network configurations.