[slurm-users] Can't use cgroups on debian 11 : unable to get parameter 'tasks' for '/sys/fs/cgroup/cpuset/'

[Christopher Samuel]

On 11/16/21 8:04 am, Arthur Toussaint wrote:

> I've seen people having those kind of problems, but no one seem to be 
> able to solve it and keep the cgroups

Debian Bullseye switched to cgroups v2 by default which Slurm doesn't 
support yet, you'll need to switch back to the v1 cgroups. The release 
notes have info on how to do this here:

https://www.debian.org/releases/stable/amd64/release-notes/ch-information.en.html#openstack-cgroups

Short version is it says you need to add this to the kernel boot params:

systemd.unified_cgroup_hierarchy=false 
systemd.legacy_systemd_cgroup_controller=false

The name of that second one looks a bit misleading, it's described in 
the systemd man page as:

https://manpages.debian.org/testing/systemd/systemd.1.en.html

 > Takes effect if the full unified cgroup hierarchy is not used (see 
previous option). When specified without an argument or with a true 
argument, disables the use of "hybrid" cgroup hierarchy (i.e. a 
cgroups-v2 tree used for systemd, and legacy cgroup hierarchy[10], 
a.k.a. cgroups-v1, for other controllers), and forces a full "legacy" 
mode. When specified with a false argument, enables the use of "hybrid" 
hierarchy.

All the best,
Chris
-- 
   Chris Samuel  :  http://www.csamuel.org/  :  Berkeley, CA, USA