lxc-start: No cgroup mounted on the system

Question

Trying to start a Linux container, I get the following:

lxc-start: No cgroup mounted on the system

OS is Debian 7.

Answer 1

LXC (or other uses of the cgroups facility) requires the cgroups filesystem to be mounted (see §2.1 in the cgroups kernel documentation). It seems that as of Debian wheezy, this doesn't happen automatically.

Add the following line to /etc/fstab:

cgroup /sys/fs/cgroup cgroup defaults

For a one-time thing, mount it manually:

mount -t cgroup cgroup /sys/fs/cgroup

Answer 2

For lxc in Debian Wheezy I use in /etc/fstab:

cgroup /sys/fs/cgroup cgroup defaults,blkio,net_cls,freezer,devices,cpuacct,cpu,cpuset,memory,clone_children 0 0

In /etc/default/grub

GRUB_CMDLINE_LINUX_DEFAULT="quiet cgroup_enable=memory,namespace"

(& don't forget to run update-grub)

It is also possible to run LXC 1.0.7 on Debian Wheezy