[lxc-devel] cgroups: support cgroups mounted in multiple places (v3)

[Michael H. Warfield]

On Sun, 2011-07-03 at 19:24 +0100, jonathan essex wrote:
> I seem to be having this same issue in a Scientific Linux 6.0 (RHEL 6
> clone) installation with lxc-0.7.4.1
> 
> lxc-checkconfig seems to think everything is OK, but when I try to
> lxc-start a container I've created, I get this error message:
> 
> lxc-start: no ns_cgroup option specified
> lxc-start: failed to spawn 'centos-test'
> lxc-start: No such file or directory - failed to remove cgroup
> '/cgroup/cpuset/centos-test'

This sounds like my "failed" case in testing with libcgroup enabled.

The fact that it's mounted on /cgroup and not /sys/fs/cgroup does not
bode well all all.


1) uname -a

2) chkconfig cgconfig

You probably need to add a line to your /etc/fstab long the lines of
this:

cgroup  /sys/fs/cgroup    cgroup  defaults        0 0

Then run the commands:

chkconfig cgconfig off
chkconfig cgred off

The reboot (I have NOT had luck manually unmounting those cgroups and
remounting as a single mount point).

If I understand Serge's comments correctly, we can not get the
multipoint mounts to work even with the patched and updated lxc package
due to the lack of "clone_children" in that kernel, so you need to
switch a single mount-point mount to get lxc to work.  Then you don't
even need the multipoint patches to get it to work though you may have
tweaks to make.

> Is this the problem under discussion? I'm new to lxc, so quite
> possible I'm just misunderstanding something.

> Happy to test the patch if someone will outline how to get it/apply
> it. (Aware that this is probably a tedious newbie type question, but
> asking anyway)

Serge or Daniel may correct me but I'm under the impression that it will
not work on that kernel, depending on the rev you report back, for RHEL
6 / SL6.

> Cheers
> Jon

Regards,
Mike
-- 
Michael H. Warfield (AI4NB) | (770) 985-6132 |  mhw at WittsEnd.com
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