I am having problems with setting hidepid=2 in LXC containers version 3.0.0. This appears on different systems. One is a Debian stretch running a proxmox kernel (4.15.17-3-pve) and the other is Ubuntu 18.04 with kernel 4.15.0-20-generic.
You can find more information about my problem in the proxmox forum (this post is from us):
Does anyone has any other hint than already written in the proxmox forum?
This is a problem which we have since about August 2016. It is a big security issue for us because multiple customers do have access to the same servers and they should not be able to see the processes of the others. Because it exists since a long time we are really looking forward to have a solution.
If you need more information, please ask!
Thanks for your responses in advanced!