# CgroupConfigError: 'not mounted for subsystem cpuset' on Cgroups v2

**URL:** <https://community.openpbs.org/t/cgroupconfigerror-not-mounted-for-subsystem-cpuset-on-cgroups-v2/4225>\
**Category:** Users/Site Administrators\
**Created:** [April 13, 2026, 6:25pm UTC](https://community.openpbs.org/t/cgroupconfigerror-not-mounted-for-subsystem-cpuset-on-cgroups-v2/4225 "2026-04-13T18:25:17Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![JvAlmeidaQ](https://yyz2.discourse-cdn.com/flex030/user_avatar/community.openpbs.org/jvalmeidaq/32/872_2.png) [@JvAlmeidaQ](https://community.openpbs.org/u/JvAlmeidaQ)\
**Post date:** [April 13, 2026, 6:25pm UTC](https://community.openpbs.org/t/cgroupconfigerror-not-mounted-for-subsystem-cpuset-on-cgroups-v2/4225/1 "2026-04-13T18:25:17Z")

</div>

Hi everyone,

I am trying to configure the `pbs_cgroups` hook for resource isolation on a compute node, but I am hitting a roadblock with the `cpuset` subsystem on Cgroups v2.

**Environment:**

- **OS:** Rocky Linux 9.6 (Linux version 5.14.0-570.21.1.el9\_6.x86\_64)

- **OpenPBS Version:** pbs\_version = 22.05.11

- **Cgroups:** v2 (Unified Hierarchy)

**The Problem:** When a job is submitted to the node, the MoM rejects it, and I get the following error in the `mom_logs`:  
Unexpected error in pbs\_cgroups handling execjob\_begin event for job 176709 (system hold set): CgroupConfigError (‘enabled: cgroups enabled but not mounted for subsystem cpuset’,)  
**Context & Configurations:** I verified that the host is indeed running Cgroups v2 and that the `cpuset` controller is available at the root level:  
**$ cat /sys/fs/cgroup/cgroup.controllers**  
cpuset cpu io memory hugetlb pids rdma misc

Since it’s v2, I already removed the legacy `cpuacct` from my configuration. Here is one part of the `pbs_cgroups.json` I imported into the master:  
{  
“cgroup\_prefix”: “pbs\_jobs”,  
“enabled”: true,  
“run\_only\_on\_hosts”: [“compute-0-X”],  
“exclude\_vntypes”: [“_no\_cgroup_”],  
“periodic\_resc\_update”: true,  
“vnode\_per\_numa\_node”: true,  
“use\_hyperthreads”: false,  
“ncpus\_are\_cores”: true,  
“discover\_gpus”: true,  
“nvidia-smi”: “/usr/bin/nvidia-smi”,  
“manage\_rlimit\_as”: true,  
“cgroup”: {  
“cpuacct”: {  
“enabled”: false,  
“exclude\_vntypes”: [“_no\_cgroup_”]  
},  
“cpuset”: {  
“enabled”: true,  
“exclude\_cpus”: ,  
“exclude\_vntypes”: [“_no\_cgroup_”],  
“allow\_zero\_cpus”: false,  
“mem\_fences”: false,  
“mem\_hardwall”: true,  
“memory\_spread\_page”: true  
},  
…

}

**My Question:** Even though `cpuset` is listed in `cgroup.controllers`, the hook says it’s not mounted. Does the PBS daemon require a manual systemd override to allow the delegation of the `cpuset` controller to the MoM on Cgroups v2? Or is there something wrong with my JSON configuration?

Any guidance would be greatly appreciated! Thanks.