cgroup: new mount options do not match the existing superblock, will be ignored

[jdfalk]

This is actually a upstream kernel warning message and should be filed against linux kernel but since I am running a mainline kernel I didn't want to file directly against the kernel.

May 14 22:21:31 kernel: cgroup: new mount options do not match the existing superblock, will be ignored

Looks like systemd is using xattr and /sys/fs/cgroup is not if I am reading this right http://www.spinics.net/lists/cgroups/msg07467.html

/var/log# mount | grep cgroup
tmpfs on /sys/fs/cgroup type tmpfs (rw,mode=755)
cgroup on /sys/fs/cgroup/systemd type cgroup (rw,nosuid,nodev,noexec,relatime,xattr,release_agent=/lib/systemd/systemd-cgroups-agent,name=systemd)
cgroup on /sys/fs/cgroup/net_cls,net_prio type cgroup (rw,nosuid,nodev,noexec,relatime,net_cls,net_prio)
cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset,clone_children)
cgroup on /sys/fs/cgroup/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio)
cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices)
cgroup on /sys/fs/cgroup/hugetlb type cgroup (rw,nosuid,nodev,noexec,relatime,hugetlb,release_agent=/run/cgmanager/agents/cgm-release-agent.hugetlb)
cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpu,cpuacct)
cgroup on /sys/fs/cgroup/memory type cgroup (rw,nosuid,nodev,noexec,relatime,memory)
cgroup on /sys/fs/cgroup/freezer type cgroup (rw,nosuid,nodev,noexec,relatime,freezer)
cgroup on /sys/fs/cgroup/perf_event type cgroup (rw,nosuid,nodev,noexec,relatime,perf_event,release_agent=/run/cgmanager/agents/cgm-release-agent.perf_event)

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: cgroup-bin (not installed)
Uname: Linux 4.1.0-040100rc3-generic x86_64
ApportVersion: 2.17.2-0ubuntu1
Architecture: amd64
Date: Fri May 15 00:01:42 2015
InstallationDate: Installed on 2015-05-10 (5 days ago)
InstallationMedia: Ubuntu-Server 15.04 "Vivid Vervet" - Release amd64 (20150422)
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: libcgroup
UpgradeStatus: No upgrade log present (probably fresh install)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Laurent Bonnaud (laurent-bonnaud)]

On my Ubuntu 16.10 system (and on Debian systems) this error message is triggered by starting lxcfs.

[Laurent Bonnaud (laurent-bonnaud)]

The bug is still there in zesty in this package version:

Package: lxcfs
Version: 2.0.6-1

[Knickers Brown (metta-crawler)]

The bug is still in artful
$ apt search lxcfs | grep lxcfs/
lxcfs/artful-updates,now 2.0.8-0ubuntu1~17.10.2 amd64 [installed]

[Knickers Brown (metta-crawler)]

The bug is still there in artful in this package version:
$ apt search lxcfs | grep lxcfs/
lxcfs/artful-updates,now 2.0.8-0ubuntu1~17.10.2 amd64 [installed]

[Stéphane Graber (stgraber)]

Closing as Invalid as there's no good way around this issue in general.

The kernel will let you mount controllers that were already mounted but will complain if options don't perfectly match. Those options may differ for a number of reason and making lxcfs match those from systemd just means, this will show up on non-systemd systems.

Similarly, you can usually expect to see this message whenever starting a container due to different init systems or even different versions of init systems using slightly different mount options.

This doesn't prevent the mount and in most cases, really just causes one line in a log file.