I'm all for open source development in every aspect. And proxmox is very inviting group of well put together software.
Where most open source software, you use the product, and get community assistance. Which proxmox also has community forums.
Most open source / free, built on the shoulders of those behind us maintains repositories, where updates whether security or features are pushed, that end users should regularly update their system from.
Such as RHEL, PFsense, and other major successful have implemented means to financially support the continued production by means of subscriptions. Well so does proxmox.
Here is where the 'rules' are bent and crinkled with proxmox.
Proxmox has decided that if you want to use their software in production, you must pay. As they state, anything else is considered 'unstable' and should not be used in production. However many of us have been using / contributing the platform over a period of time, before the 'stable' repos were removed to subscription only.
As of this time (nearly six months since the 3.3 release) there is no 'fail-safe' upgrade process, unless of course you pay. I should state, this means you cannot update to the latest version. Security? That is anyones guess. And I am now guessing.
Sure, there appears to be a community solution, after attempting this on a local dev, the troubles were more than I was willing to risk in a production environment.
Fair enough, time to search out viable alternatives and never look back.
Now ask the proxmox staff why they choose to go this route, their answer is simple, clone the repo and compile the binaries yourself. Hmm, nice skate of the license there. After all, they are available, just not really usable. As one would be compelled to devote extended periods of time, where time could be spent elsewhere, more productive.
My thoughts, they should completely phase out the 'free' aspect, and go full subscription only, immediately. As proxmox does not fit into the open source model I've always known. Yes, open source does not mean free, however using people as guinea pigs to develop and bug fix, then turning around and shutting out those that assisted the development, is uncool.
Simple words of warning, play, use proxmox, real life, either pay or don't even bother, move along away from proxmox.