Compatibility Warning: Container Requires systemd v232+ for cgroupv2 Environment

Servers
, , , , , , ,
1

How to Resolve LXC Startup Error on Proxmox from v6 to v7

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:

  1. Edit the GRUB configuration file on your Proxmox 7 server using a text editor like nano:

    nano /etc/default/grub

  2. Locate the GRUB_CMDLINE_LINUX_DEFAULT parameter.

  3. Add the following configuration to the line, preserving the existing parameters:

    quiet systemd.unified_cgroup_hierarchy=0

    The line should look like this:

    GRUB_CMDLINE_LINUX_DEFAULT="quiet systemd.unified_cgroup_hierarchy=0"

  4. Save the file.

  5. Run the following command to update the GRUB configuration:

    update-grub

  6. Restart the server to apply the changes:

    reboot

By adding 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.

2

beware, if you copy/paste this config line verbatim line, the quotes come out wrong. you don’t want mistakes in your grub config!

it should be this:
GRUB_CMDLINE_LINUX_DEFAULT=“quiet systemd.unified_cgroup_hierarchy=0”

and not this:
GRUB_CMDLINE_LINUX_DEFAULT=“quiet systemd.unified_cgroup_hierarchy=0”

3

Thanks @darxtorm now the quotes are fixed, you can copy and paste.