Suggestion

[falves1]

I brought in my existing LXC containers into Debian, and they work perfectly, I can manage them with the regular lxc command list. But Proxmox only shows its own containers, not all LXC containers. Proxmox containers must coexist and be managed along with regular LXC, directory-backed containers. Why would Proxmox ignore regular LXC containers?

 

[kotakomputer]

Just backup then restore it to Proxmox.

 

[falves1]

Maybe I am misunderstanding the Proxmox LXC model. The free, regular LXC containers are invisible to Proxmox.
Please correct me if I am wrong.

 

[kotakomputer]

LXC by Proxmox not 100% same as regular LXC, Proxmox has added features like Firewall, User Access, User Group, etc which integrated using Proxmox UI. To make us simpler, Proxmox has wrap all complexity into "pct" tools.

So, to make you regular LXC become Proxmox UI member, then simple backup and restore your regular LXC into Proxmox.