If you encounter the following warning when starting an LXC container after upgrading from Proxmox v6 to v7:
WARN: old systemd (< v232) detected, container won't run in a pure cgroupv2 environment! Please see documentation -> container -> cgroup version.
Here is a solution to address this issue:
Edit the GRUB configuration file on your Proxmox 7 server using a text editor like
Add the following configuration to the line, preserving the existing parameters:
The line should look like this:
Save the file.
Run the following command to update the GRUB configuration:
Restart the server to apply the changes:
systemd.unified_cgroup_hierarchy=0 to the GRUB configuration, you revert the CGroup version to version 1. Proxmox 7 predominantly uses version 2, but this adjustment will ensure compatibility.
Alternatively, you can consider either installing a newer version of systemd or migrating your machine to CentOS 8 or a more recent distribution.
If you require further assistance, it is recommended to reach out to Proxmox support for additional help and guidance.