The /cgroup filesystem is not mounted


I'm trying to add LXC Host systems and am getting the following error:

ailed to save LXC host : The selected system cannot support LXC containers : The /cgroup filesystem is not mounted

Do you know how I can correct the above?




Howdy -- what does the command "mount" show on your server?

Howdy doody. We have :

/dev/mapper/duke--vg-root on / type ext4 (rw,errors=remount-ro)
proc on /proc type proc (rw,noexec,nosuid,nodev)
sysfs on /sys type sysfs (rw,noexec,nosuid,nodev)
none on /sys/fs/cgroup type tmpfs (rw)
none on /sys/fs/fuse/connections type fusectl (rw)
none on /sys/kernel/debug type debugfs (rw)
none on /sys/kernel/security type securityfs (rw)
udev on /dev type devtmpfs (rw,mode=0755)
devpts on /dev/pts type devpts (rw,noexec,nosuid,gid=5,mode=0620)
tmpfs on /run type tmpfs (rw,noexec,nosuid,size=10%,mode=0755)
none on /run/lock type tmpfs (rw,noexec,nosuid,nodev,size=5242880)
none on /run/shm type tmpfs (rw,nosuid,nodev)
none on /run/user type tmpfs (rw,noexec,nosuid,nodev,size=104857600,mode=0755)
none on /sys/fs/pstore type pstore (rw)
/dev/sda1 on /boot type ext2 (rw)
systemd on /sys/fs/cgroup/systemd type cgroup (rw,noexec,nosuid,nodev,none,name=systemd)

This is a bug in the current release of Cloudmin - it doesn't check the /sys/fs/cgroup filesystem for cgroups. However, it will be fixed in the next release.

Which Linux distribution & version is your host system running though?

Hi Jamie.

My Distro is Ubuntu Server 14.04.1 LTS

Is there a workaround in the short term?

I could send you a pre-release Cloudmin update to test if you like?

Just let me know which OS your Cloudmin master runs.

Hi Jamie,

We're on Ubuntu Server 14.04.1 LTS

Cheers, Ryan

Actually, I just realized that the new version might not fix this issue, because the /sys/fs/cgroup filesystem type is not cgroup (which is odd). Can you also post the contents of the /etc/mtab file on your system?

Also, can you confirm that commands like cgcreate are installed on your system?

Hi Jamie,

This was a stock install of LXC after installing Cloudmin .. Here's my mtab:

/dev/mapper/duke--vg-root / ext4 rw,errors=remount-ro 0 0
proc /proc proc rw,noexec,nosuid,nodev 0 0
sysfs /sys sysfs rw,noexec,nosuid,nodev 0 0
none /sys/fs/cgroup tmpfs rw 0 0
none /sys/fs/fuse/connections fusectl rw 0 0
none /sys/kernel/debug debugfs rw 0 0
none /sys/kernel/security securityfs rw 0 0
udev /dev devtmpfs rw,mode=0755 0 0
devpts /dev/pts devpts rw,noexec,nosuid,gid=5,mode=0620 0 0
tmpfs /run tmpfs rw,noexec,nosuid,size=10%,mode=0755 0 0
none /run/lock tmpfs rw,noexec,nosuid,nodev,size=5242880 0 0
none /run/shm tmpfs rw,nosuid,nodev 0 0
none /run/user tmpfs rw,noexec,nosuid,nodev,size=104857600,mode=0755 0 0
none /sys/fs/pstore pstore rw 0 0
cgroup /sys/fs/cgroup/cpuset cgroup rw,relatime,cpuset,release_agent=/run/cgmanager/agents/cgm-release-agent.cpuset,clone_children 0 0
cgroup /sys/fs/cgroup/cpu cgroup rw,relatime,cpu,release_agent=/run/cgmanager/agents/cgm-release-agent.cpu 0 0
cgroup /sys/fs/cgroup/cpuacct cgroup rw,relatime,cpuacct,release_agent=/run/cgmanager/agents/cgm-release-agent.cpuacct 0 0
cgroup /sys/fs/cgroup/memory cgroup rw,relatime,memory,release_agent=/run/cgmanager/agents/cgm-release-agent.memory 0 0
cgroup /sys/fs/cgroup/devices cgroup rw,relatime,devices,release_agent=/run/cgmanager/agents/cgm-release-agent.devices 0 0
cgroup /sys/fs/cgroup/freezer cgroup rw,relatime,freezer,release_agent=/run/cgmanager/agents/cgm-release-agent.freezer 0 0
cgroup /sys/fs/cgroup/blkio cgroup rw,relatime,blkio,release_agent=/run/cgmanager/agents/cgm-release-agent.blkio 0 0
cgroup /sys/fs/cgroup/perf_event cgroup rw,relatime,perf_event,release_agent=/run/cgmanager/agents/cgm-release-agent.perf_event 0 0
cgroup /sys/fs/cgroup/hugetlb cgroup rw,relatime,hugetlb,release_agent=/run/cgmanager/agents/cgm-release-agent.hugetlb 0 0
/dev/sda1 /boot ext2 rw 0 0
systemd /sys/fs/cgroup/systemd cgroup rw,noexec,nosuid,nodev,none,name=systemd 0 0

I can confirm that cgcreate is installed as /usr/bin/cgcreate


I just installed cloudmin 8.4 on a debian stretch. Exact same issue here. mtab and the mounted filesystem look more or less the same as with the original poster. Is there any fix for that as the issue was raised almost 2 years ago.

Best Regards Janos

Can anyone who is seeing this post the output from the mount command?

Hi Jamie, on latest debian (Debian GNU/Linux 8 (jessie)), I have this issue (The /cgroup filesystem is not mounted).

To solve I have added "tmpfs" in file /usr/share/webmin/server-manager/ at line 2057, so now come: if ($out !~ /(tmpfs|cgroup|cgroups|none)\s+on\s+(\/cgroup|\/cgroups|\/sys\/fs\/cgroup)\s/) { in according with my "mount" output

sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
udev on /dev type devtmpfs (rw,relatime,size=10240k,nr_inodes=4093191,mode=755)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)
tmpfs on /run type tmpfs (rw,nosuid,relatime,size=6552448k,mode=755)
/dev/sda2 on / type ext4 (rw,relatime,quota,usrquota,grpquota,errors=remount-ro,data=ordered)
securityfs on /sys/kernel/security type securityfs (rw,nosuid,nodev,noexec,relatime)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev)
tmpfs on /run/lock type tmpfs (rw,nosuid,nodev,noexec,relatime,size=5120k)
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)
pstore on /sys/fs/pstore type pstore (rw,nosuid,nodev,noexec,relatime)
cgroup on /sys/fs/cgroup/cpuset type cgroup (rw,nosuid,nodev,noexec,relatime,cpuset,clone_children)
cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup (rw,nosuid,nodev,noexec,relatime,cpu,cpuacct)
cgroup on /sys/fs/cgroup/devices type cgroup (rw,nosuid,nodev,noexec,relatime,devices)
cgroup on /sys/fs/cgroup/freezer type cgroup (rw,nosuid,nodev,noexec,relatime,freezer)
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/blkio type cgroup (rw,nosuid,nodev,noexec,relatime,blkio)
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)
systemd-1 on /proc/sys/fs/binfmt_misc type autofs (rw,relatime,fd=22,pgrp=1,timeout=300,minproto=5,maxproto=5,direct)
mqueue on /dev/mqueue type mqueue (rw,relatime)
debugfs on /sys/kernel/debug type debugfs (rw,relatime)
hugetlbfs on /dev/hugepages type hugetlbfs (rw,relatime)
/dev/sda1 on /boot/efi type vfat (rw,relatime,fmask=0077,dmask=0077,codepage=437,iocharset=utf8,shortname=mixed,errors=remount-ro)
rpc_pipefs on /run/rpc_pipefs type rpc_pipefs (rw,relatime)
cgmfs on /run/cgmanager/fs type tmpfs (rw,relatime,size=100k,mode=755)

Still I found another issue about LXC: when root user try to create a new LXC system then missing submit button. See screenshot at


Thanks - I'll include that fix!