wtf is pretty-safe-upgrade-proxmox-8-to-9?

Pretty-Safe-Upgrade-Proxmox-8-to-9 is a shell script that guides you through upgrading a single Proxmox VE 8 server to Proxmox VE 9, which under the hood means moving the underlying Debian operating system from version 12 to version 13. Rather than replacing the official Proxmox upgrade guide, it automates the mechanical steps of that guide and adds safety checks around them, while still asking your permission before doing anything meaningful. The script is built for the simple case: a single server that is not part of a cluster, without integrated Ceph storage, and without a co-installed Proxmox Backup Server. If it detects Ceph or PBS anyway, it warns you and asks for explicit confirmation before continuing, though it does not perform those upgrades itself. Before starting, you need Proxmox VE 8.4.1 or newer, root access, at least 10 GB of free disk space, and ideally a physical or IPMI console rather than SSH, since the network can drop mid-upgrade. A tested backup of all your virtual machines and containers is also expected, and the script can take one for you if you do not already have one. The upgrade runs in eight steps: backing up your guests, updating to the latest Proxmox 8.4, running Proxmox's own readiness checker, quieting audit log noise, switching the system's software repositories from Bookworm to Trixie, running the actual dist-upgrade, rebooting into the new kernel, and finally verifying that everything came up correctly on version 9. Every action requires a yes or no confirmation, with destructive steps defaulting to no. If a step fails, the script stops with a clear message, logs everything to a timestamped file, and can simply be run again later, since it tracks which steps already finished and skips them. A reboot partway through the process is expected and handled the same way. A reset flag is available if you want to start completely over.