Comment # 3 on bug 1202821 from Michal Koutn���

(In reply to Fabian Vogt from comment #2)
> All of them use practically identical systemd units and FWICT it's random
> which of the containers fails in which way...

To deal with the randomness. I'd suggest enabling debug logging of systemd and
capture the journal logs when first issue occurs (few periods back, where I
understand period~a single container lifetime).
Could you collect such data? (Or possibly just share journal data that you have
for the current instance (without debug level).)

> I tried that (without typo, "systemd.unified_cgroup_hierarchy=1"). 

Sorry about that, it hits me all the time. `man systemd` is correct.

> The kernel parameter is used, but it looks like cgroupv1 is still used by
> systemd, at least for devices. Is that expected?

No, that's suspicious. The device controller functionality is replaced with BPF
programs with unified mode. (Isn't it still the typo? ':-))
What does `grep cgroup /proc/mounts` say on such a system?

> Also, this is not the default, so IMO even if it works with unified it
> should still be fixed with cgv1 or the default changed.

Understood.