The memory on

in the free命令，看的是Hostcontainer.

To check the memory limit of container use this:

cat /cgroup/memory/lxc/{full_container_id}/memory.limit_in_bytes

/cgroup/:

ll /cgroup/
总用量 0
drwxr-xr-x 3 root root 0 3月  17 13:33 blkio
drwxr-xr-x 3 root root 0 3月  17 13:33 cpu
drwxr-xr-x 3 root root 0 3月  17 13:33 cpuacct
drwxr-xr-x 3 root root 0 3月  17 13:33 cpuset
drwxr-xr-x 3 root root 0 3月  17 13:33 devices
drwxr-xr-x 3 root root 0 3月  17 13:33 freezer
drwxr-xr-x 3 root root 0 3月  17 13:33 memory
drwxr-xr-x 3 root root 0 3月  17 13:33 net_cls

Owner, I also encountered this problem when I was doing experiments with Ubuntu virtual machine. Please refer to here to solve it
http://docs.docker.com/articles/runmetrics/
The following are key excerpts

If you want to enable memory and swap accounting, you must add the following command-line parameters to your kernel:

$ cgroup_enable=memory swapaccount=1

On systems using GRUB (which is the default for Ubuntu), you can add those parameters by editing /etc/default/grub and extending GRUB_CMDLINE_LINUX. Look for the following line:

$ GRUB_CMDLINE_LINUX=""

And replace it by the following one:

$ GRUB_CMDLINE_LINUX="cgroup_enable=memory swapaccount=1"

Then run sudo update-grub, and reboot.

These parameters will help you get rid of the following warnings:

WARNING: Your kernel does not support cgroup swap limit.
WARNING: Your kernel does not support swap limit capabilities. Limitation discarded.

Does anyone know how to solve this problem on Centos6?
My docker is 1.6.2, Centos is 6.6, and the kernel version is 3.10.81

@colin5063

I am CentOS6.7, it should be almost the same

I modified it/etc/grub.conf 在当前使用的内核的kernel项的最后加上cgroup_enable=memory swapaccount=1

reboot

Then cat /proc/cmdline you will find that the configuration has taken effect