Ubuntu 16.04 Container Template Download Within PVE 7.1?

[uberdome]

I'm curious, why is the Ubuntu 16.04 Container Template still downloadable from within PVE 7.1?

I tested it out just to see if it had built-in adjustments to run cgroupv2 and be compatible with PVE 7, but it does not.

Can the available template list be adjusted to only be ones that are directly compatible upon download?

 

[oguz]

hi,

I tested it out just to see if it had built-in adjustments to run cgroupv2 and be compatible with PVE 7, but it does not.

yes this is already documented [0]. see the part about systemd version (that's the main reason it's not working in the cgroupv2 environment).

why is the Ubuntu 16.04 Container Template still downloadable from within PVE 7.1

the templates list doesn't differ between different PVE versions (for older installations 16.04 still works out of the box).

Can the available template list be adjusted to only be ones that are directly compatible upon download?

if you want to use the ubuntu 16.04 template you can try upgrading the systemd version inside it (as suggested in our wiki) or switch to the unified hierarchy.

[0]: https://pve.proxmox.com/pve-docs/chapter-pct.html#pct_cgroup_compat

 

[uberdome]

yes this is already documented [0]. see the part about systemd version (that's the main reason it's not working in the cgroupv2 environment).

I just went through fixing this issue with existing 16.04 containers. I tried downloading the template to see if it had this problem resolved internally since it showed as available.

the templates list doesn't differ between different PVE versions (for older installations 16.04 still works out of the box).

I think it could be very useful for the list to differ between versions. Having these templates available for download from within PVE seems to imply compatibility. If I wasn't just experimenting and hadn't just had to fix other 16.04 containers, I wouldn't have known this clearly. Especially for anyone starting with PVE in 7.x and not seeing the cgroup2 documentation, starting one of these templates seems benign but results in an immediate challenge.

 

[t.lamprecht]

I think it could be very useful for the list to differ between versions. Having these templates available for download from within PVE seems to imply compatibility

Well, it is compatible and works out after bringing up network manually or for those users that switched back to the old CGroup hierarchy for now https://pve.proxmox.com/pve-docs/chapter-pct.html#pct_cgroup

Why should we punish those that can work with such a template just because it cannot work on every system out of the box, especially as nobody is forced to use it? We keep old templates available for download in general, but de-index them if they got EOL. FWIW, 16.04 is still covered by Ubuntu's extended support release policy.

 

[uberdome]

Why should we punish those that can work with such a template just because it cannot work on every system out of the box, especially as nobody is forced to use it? We keep old templates available for download in general, but de-index them if they got EOL. FWIW, 16.04 is still covered by Ubuntu's extended support release policy.

I appreciate your position: "why punish those who can solve this problem". If we're using that rhetoric, I suppose I would respond with: "why punish the majority of users and systems that have not been specifically customized to work with older containers?" I feel like Proxmox does a really good job of making sure things generally work. This just seems counter to the logical path Proxmox has followed.

You're right, nobody is being forced to use those templates. Compatibility is not guaranteed, but having templates right there does make compatibility seem implicit.

I recognize 16.04 is LTS and still supported; and that is why I personally have so many containers running it. To me, it makes more sense for me to have to dig to get a template that only works with a custom setup... than for that template that doesn't normally work to be readily available to everyone [at least without some ready disclaimer].

It isn't some big problem, I was just wondering what the reasoning was, and suggesting that there might be an alternative method.

 

[t.lamprecht]

suppose I would respond with: "why punish the majority of users and systems that have not been specifically customized to work with older containers?"

As said, nobody forces you to use it, so you're not punished in that sense, but people relying on it would be, if it wouldn't be available anymore. Users won't use ~6 year old distros anyway for new setups if not required for some compat stuff, and if they'll need it and happy that even if some work is required it's way easier than additionally needing to come up with their own template.

It isn't some big problem, I was just wondering what the reasoning was, and suggesting that there might be an alternative method.

You can certainly send patches if you want to add some cgroup-aware filter for the template download index, we're not investing work into that one as it will phase naturally out in one or two years anyway, once all templates that have some initial hiccups with cgroupv2 will be phased out due to being EOL.