Re: [libvirt] [systemd-devel] systemd-cgroups-agent not working in containers

Hello all, Cameron Norman [2014-11-27 12:26 -0800]: > On Wed, Nov 26, 2014 at 1:29 PM, Richard Weinberger <richard(a)nod.at&gt; wrote: >> Hi! >> >> I run a Linux container setup with openSUSE 13.1/2 as guest distro. >> After some time containers slow down. >> An investigation showed that the containers slow down because a lot of stale >> user sessions slow down almost all systemd tools, mostly systemctl. >> loginctl reports many thousand sessions. >> All in state "closing". > > This sounds similar to an issue that systemd-shim in Debian had. > Martin Pitt (helps to maintain systemd in Debian) fixed that issue; he > may have some ideas here. I CC'd him. The problem with systemd-shim under sysvinit or upstart was that shim didn't set a cgroup release agent like systemd itself does. Thus the cgroups were never cleaned up after all the session processes died. (See 1.4 on https://www.kernel.org/doc/Documentation/cgroups/cgroups.txt for details) I don't think that SUSE uses systemd-shim, I take it in that setup you are running systemd proper on both the host and the guest? Then I suggest checking the cgroups that correspond to the "closing" sessions in the container, i. e. /sys/fs/cgroup/systemd/.../session-XX.scope/tasks. If there are still processes in it, logind is merely waiting for them to exit (or set KillUserProcesses in logind.conf). If they are empty, check that /sys/fs/cgroup/systemd/.../session-XX.scope/notify_on_release is 1 and that /sys/fs/cgroup/systemd/release_agent is set?