[lxc-users] Debian and unprivileged LXC not working...

[Serge E. Hallyn]

Quoting Dirk Geschke (dirk at lug-erding.de):
> Hi Serge,
> 
> > > I am a little bit clueless, I have several systems running with
> > > Debian and unprivileged LXC. But newer systems won't start new
> > > containers.
> > > 
> > > Actually I have a Debian stretch, installed the normal way but
> > > with lxc-2.0.9 and cgmanager-0.41 installed from sources.
> > > 
> > > I can setup cgmanager, can do a cgm movepid and it is no problem
> > > to download a template. But starting the container does not work,
> > > it simply hungs at:
> > > 
> > >    $ lxc-start -n lxc-test -l trace -o wheezy -F
> > 
> > I see no bad errors in the log.  When this hangs, can you
> > from another terminal see whether 'lxc-ls -f' shows it
> > running, and what 'lxc-attach -n lxc-test' does?
> 
> that's the funny part: Nothing. There is not one process from 
> the subuid range running. It simply hangs before it tries to 
> start the container at all. And I have no idea, why.
> But with lxc-2.0.8 it works. 
> 
> I just installed and started debian wheezy, upgraded it to jessie
> and finally to stretch. It works fine.
> 
> I now installed lxc-2.0.9 again, tried to start the container again
> and nothing happens:
> 
>    $ lxc-start -n lxc-test -l trace -o stretch-lxc-2.0.9 -F
> 
> That's all. lxc-ls -f and lxc-attach-n lxc-test hangs, too.
> 
> I see also three processes of lxc-start:
> 
>    $ ps waux |grep lxc-start
>    lxc-test 24478  0.0  0.1  51740  4232 pts/0    S+   17:16   0:00
>    lxc-start -n lxc-test -l trace -o stretch-lxc-2.0.9 -F
>    lxc-test 24487  0.0  0.0  51740   504 pts/0    S+   17:16   0:00
>    lxc-start -n lxc-test -l trace -o stretch-lxc-2.0.9 -F
>    lxc-test 24492  0.0  0.0  51740   508 pts/0    S+   17:16   0:00
>    lxc-start -n lxc-test -l trace -o stretch-lxc-2.0.9 -F
> 
> That's really strange...

Can you (install dbgsym pkg if you need to and) gdb attach to
the lxc-start process, and figure out where it's sitting?