For reference: uname -r: 5.2.13-gentoo, systemd version 243_rc2-r1[cgroup-hybrid], ACCEPT_KEYWORDS="~amd64"
My system started failing to start running docker.service automatically and the logs weren't too helpful. Finally I ran dockerd on its own and found that it gave me this error message: Devices cgroup isn't mounted This is not too easy to diagnose as there seem to be a set of solutions but none of the main two worked for me. One involved setting 2 options on the kernel command line: cgroup_enable=memory swapaccount=1 And the other was to add USE="cgroup-hybrid" to systemd. I did this, but it too it did not work. The other solution is to simply mount the cgroup manually and this works but I did not see why I'd have to do that now when I never had to in the past. I actually had to add this to my command line: systemd.legacy_systemd_cgroup_controller=yes This has been noted in other distros but from what I can tell this is solely because runc has not been updated to be able to use cgroups v2. Anyone else ran into this issue? Is there something I am missing so I wouldn't need to pass a kernel command line option? Reference links: https://docs.docker.com/install/linux/linux-postinstall/#your-kernel-does-not-support-cgroup-swap-limit-capabilities https://github.com/opencontainers/runc/issues/654 https://github.com/opencontainers/runc/issues/1175 https://wiki.gentoo.org/wiki/Docker#Docker_service_fails_because_cgroup_device_not_mounted_.28systemd.29 -- Andrew Udvare
