[Lxc-users] LXC with multiple cgroup mount points

[Serge Hallyn]

Quoting Ramez Hanna (rhanna at informatiq.org):
> On Sat, Jan 28, 2012 at 2:56 PM, Jimmy THRASIBULE
> <thrasibule.jimmy at gmail.com> wrote:
> > Hi,
> >
> > I'm running Fedora 16 and I'm trying to run an LXC container. I think
> > that my problem comes from how Fedora mount the different cgroup
> > subsystems. Each subsystem is mounted on its own file system:
> >
> > tmpfs on /sys/fs/cgroup type tmpfs
> > (rw,nosuid,nodev,noexec,relatime,seclabel,mode=755)
> > cgroup on /sys/fs/cgroup/systemd type cgroup
> > (rw,nosuid,nodev,noexec,relatime,release_agent=/lib/systemd/systemd-cgroups-agent,clone_children,name=systemd)
> > cgroup on /sys/fs/cgroup/cpuset type cgroup
> > (rw,nosuid,nodev,noexec,relatime,cpuset)
> > cgroup on /sys/fs/cgroup/cpu,cpuacct type cgroup
> > (rw,nosuid,nodev,noexec,relatime,cpuacct,cpu)
> > cgroup on /sys/fs/cgroup/memory type cgroup
> > (rw,nosuid,nodev,noexec,relatime,memory)
> > 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 type cgroup
> > (rw,nosuid,nodev,noexec,relatime,net_cls)
> > 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)
> >
> > When I try to start my container, here is what I get:
> >
> > # lxc-start -f config -n generic
> > lxc-start: open /sys/fs/cgroup/systemd/generic/devices.deny : No such
> > file or directory
> > lxc-start: failed to setup the cgroups for 'generic'
> > lxc-start: failed to setup the container
> > lxc-start: invalid sequence number 1. expected 2
> > lxc-start: failed to spawn 'generic'
> >
> > You can find the full log file enclosed with the container configuration file.
> >
> > LXC seems to pick the first cgroup subsystem it can get but as that
> > subsystem does not allow the full cgroup operations, LXC fails to
> > start the container. I cannot mount a full cgroup file system as one
> > is already mounted:
> >
> > # mount -t cgroup lxc /cgroup
> > mount : lxc is already mounted or /cgroup is busy
> >
> > What can I do in this kind of situation? Can I specify to LXC where it
> > can find all the cgroup subsystems?
> >
> > ___
> > Jimmy THRASIBULE <thrasibule.jimmy at gmail.com>
> >
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> 
> which lxc version are u using?
> I can get past this step but I have other issues related to systemd or
> at least that's what i concluded
> I am using the latest GIT version
> the one problem i get related to multiple cgroups is the stoping
> when i stop a container it fails to remove all the cgroups ctreated
> so I need to do
> cd /sys/fs/cgroup
> for cg in $(find -type d -name $container_name); do find $cg -type d
> -exec rmdir -p '{}' \;;done

Note that github.com/hallyn/lxc is staging some patches which should fix
those issues.  They'll hit lxc.sf.net at some point, but they may change
a bit first.

-serge