[fChk]

And No!.. the problem is not Cgroups' support in your case, because CGroups are supported starting in Linux kernel 3.10; it's CGroups v2 that are implemented in kernel 4.15. And Docker engine requires CGroups v1 (v2 is still not supported by Docker last time I checked) for its process isolation for the containers it runs.

I had to comeback to this thread to correct and update the information conveyed in quote of mine.

I've said that 'CGroups are supported starting in Linux kernel 3.10' which is factually WRONG!.. As Control groups (cgroups v1) were merged into the Linux kernel since version 2.6.24, around 2007.

So where that kernel 3.10 come from?.. Well it's the absolute minimum kernel version that supports the features that Docker requires to run stable. Although, technically, you can still run Docker on a kernel 2.6.24 with a lot of hacks, exactly what OpenVZ was doing since then..

Same thing for CGroups v2 (aka unified hierarchy):
> CGroups v2 were first merged in kernel 4.5 but enabling cgroup v2 for containers required kernel 4.15 or later.

So basically my mind was focused on specific kernel versions pertaining to Docker support vis-a-vis of CGroups v1 and v2 while talking about CGroups in general in that quote. My mistake!

The other important update to add here is relative to this part of the quote:

(...) And Docker engine requires CGroups v1 (v2 is still not supported by Docker last time I checked) for its process isolation for the containers it runs.

As of Docker version 20.10 support of cgroup v2 and Rootless mode is now added.

Great news for Fedora users which switched to CGroups v2 by default since Fedora 31, released on October 29, 2019!

Since then it was imperative to resort to a hack to run Docker on that system which I've reluctantly done till I decided to migrate my Docker setup inside a KVM VM running CentOS 8 (actually the same VM that I've cloned from my old Phoenix VPS.)