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nealmcb
Asked: 2013-12-29 13:18:59 +0800 CST

Ubuntu cgroup architecture: cgroup-lite vs cgroup-bin and default config for lxc, libvirt-bin?

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It seems that (at least in Ubuntu 12.04 Precise), the cgroup-lite package is used to provide some cgroup capabilities for packages like libvirt-bin and lxc. It sets up a number of cgroups in /sys/fs/cgroup for example.

I was reading the very nice documentation on cgroups for redhat and I wanted to use some of the other cgroup commands that are only in cgroup-bin. But when I installed that, /sys/fs/cgroup became empty, presumably because the cgroup-lite package was uninstalled since it conflicts with cgroup-bin.

What am I missing after having done this? Is there a way to get the same default set of cgroups that cgroup-lite sets up? Is there any documentation for the cgroup definition that cgroup-lite provides?

The lxc documentation in the server guide talks a bit about cgroup-lite, but seems to assume that cgroup-lite will be installed, which won't be true if either recommended packages are skipped, or the alt]ernative, cgroup-bin, is installed.

lxc

1 Answers

  1. Best Answer

    You can get the same cgroup management files just by adding the /cgroup mount to your fstab:

    cgroup          /cgroup         cgroup  defaults        0       0

    The files end up in a slightly different location. With cgroup-lite, you will end up with paths like /sys/fs/cgroup/cpu/cpu.shares, whereas with the fstab method you'll get /cgroup/cpu.shares.

    The cgroup-lite package itself is just providing an init script to mount those control directories if they don't yet exist via fstab or some other means.

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