What were you trying to do that didn't work?

After rebooting, the upgrade fails early while trying to mount the cgroup v2. This was at most a tech preview on RHEL 7.

Please provide the package NVR for which bug is seen:

leapp-repository-0.19

How reproducible:

Always for the customer.

On my side, leapp hung during the upgrade step, before the reboot.

Steps to reproduce

Add the below parameter to the cmdline

systemd.unified_cgroup_hierarchy=1

leapp upgrade

Expected results

Ideally an inhibitor. Being likely too late in the RHEL 7 life cycle for this very rare issue, a KCS could be enough.

Actual results

[ 4.697911] localhost upgrade[586]: Failed to mount n/a on /sys/fs/cgroup (MS_RDONLY|MS_NOSUID|MS_NODEV|MS_NOEXEC|MS_REMOUNT|MS_STRICTATIME "mode=755"): Invalid argument
[ 4.694476] localhost kernel: cgroup2: Unknown parameter 'mode'
[ 4.715174] localhost upgrade[584]: Child died too early.