Updating Proxmox VM ISO image for Plakar Control Plane

Plakar Control Plane is distributed on Proxmox as a virtual appliance, deployed by creating a VM and booting it from the Plakar Control Plane appliance ISO.

Most Plakar Control Plane updates can be installed directly from the settings page without touching the VM. However, in rare cases, the underlying appliance ISO also needs to be updated. This usually happens when infrastructure-level changes are required.

The appliance ISO is immutable and runs entirely in RAM. Its contents do not persist across reboots. Persistent Plakar Control Plane data and configuration are stored on the VM’s disk (scsi0).

Because the appliance is separated from its persistent data, updating the appliance does not require replacing the VM or its disk. Swapping the mounted ISO and restarting the existing VM is enough. The new ISO boots using the same persistent disk.

The update process consists of:

1. Uploading the new ISO
2. Stopping the VM
3. Swapping the mounted ISO
4. Starting the VM
5. Verifying the update

Download the newer Plakar Control Plane appliance ISO from the downloads page and upload it to the ISO Images section of the same Proxmox storage used for the current ISO. Refer to Uploading the ISO in the Proxmox installation guide for details.

Stop the currently running Plakar Control Plane VM.

qm stop <vmid>

Point ide2 to the newly uploaded ISO.

qm set <vmid> -ide2 <storage>:iso/<new-iso-filename>,media=cdrom

Confirm the change:

qm config <vmid>

Start the VM.

qm start <vmid>

The appliance boots from the new ISO and uses the existing persistent disk. inventories, schedules, policies, configuration, and other Plakar Control Plane data will remain intact.

Once the VM is reachable on the network, open Plakar Control Plane in a browser as usual and confirm that the appliance is running the new version and that existing data is present.