document that compute nodes need to use cgroupsv1 / cgroupsfs for Docker
If you have the following versions
linux kernel > 4.x
systemd > 247 (en debian family)
docker > 20.10
Is very likely that you have cgroupsv2 enable by default. You can check by doing
if [ -e /sys/fs/cgroup/cgroup.controllers ] then echo "cgroupsV2 enabled" fi
Unfortunately Arvados 2.1 doesn't have support for cgrupsV2 so compute nodes need to have this disabled
this can be done by adding `systemd.unified_cgroup_hierarchy=0` to the kernel parameters.
Debian / Ubuntu:
in /etc/default/grub make sure that you have
dnf install -y grubby grubby --update-kernel=ALL --args=”systemd.unified_cgroup_hierarchy=0"
Updated by Lucas Di Pentima almost 3 years ago
I think it would be useful to explain why cgroups v2 accounting should be turned off, and if the fact of having it enabled makes the system completely fail or just some specific feature to not work properly.
I'm thinking that a preexisting Slurm Cluster admin who is looking for installing Arvados in it may wonder if it's a hard requirement or if they could live with the limitations related to keeping cgroups v2 turned on in the case that it's required by other cluster services.
Other than that, it LGTM.