A Proxmox subscription

The Proxmox VE itself is free. There are absolutely no costs involved in simply downloading the ISO image and installing a fully-functional Proxmox cluster without paying for a license or subscription. However, there is a Proxmox subscription option available to support the project, which enables enterprise repository. There are no feature differences between the Free and Subscription versions of Proxmox. Both are exactly the same. The difference is between the type of releases, updates, and patches they receive.

Tip

Packages from the enterprise repository go through an extra layer of scrutiny and testing. Thus, a subscription is recommended for a production-level Proxmox VE.

This not to be confused with the fact that a Proxmox cluster is built with no subscription and is not stable enough to use. New packages are usually released through a no-subscription repository first. Same packages are pushed through the Enterprise repository at a later time. This delay allows the Proxmox team to pin point and fix any lingering bugs or defects in the package. In a cluster running mission critical virtual machines may face unacceptable downtime due to the bug, which will not affect a smaller environment that is able to sustain downtime.

There are four levels of subscription at various price points, such as COMMUNITY, BASIC, STANDARD, and PREMIUM. For more information on the Proxmox subscription, visit https://www.proxmox.com/proxmox-ve/pricing.