[lxc-users] Fwd: Error creating cgroups

[Serge Hallyn]

Quoting Shibashish (shib4u at gmail.com):
> I had 3 VMs running on my host, the second vm crashed. I rebooted the host
> after which I am not able start any lxc container. When I start the lxc
> virtual host, it says...
> 
> *lxc-start: Error creating cgroups*
> *lxc-start: failed to spawn 'myhostvm1'*
> 
> [root@ myhost ~]# uname -a
> Linux myhost 2.6.32-431.3.1.el6.x86_64 #1 SMP Fri Jan 3 21:39:27 UTC 2014
> x86_64 x86_64 x86_64 GNU/Linux
> 
> [root@ myhost ~]# cat /etc/redhat-release
> CentOS release 6.5 (Final)
> 
> [root at myhost ~]# cat /proc/mounts | grep cgroup
> none /cgroup cgroup
> rw,relatime,net_prio,perf_event,blkio,net_cls,freezer,devices,memory,cpuacct,cpu,ns,cpuset
> 0 0
> 
> [root@ myhost ~]# mount | grep cgroup
> none on /cgroup type cgroup (rw)
> 
> Strace output...
> munmap(0x7f6910596000, 4096)            = 0
> access("/cgroup/lxc/myhostvm1", F_OK)    = -1 ENOENT (No such file or
> directory)
> mkdir("/cgroup/lxc/myhost vm1", 0755)     = -1 EINVAL (Invalid argument)
> write(3, "      lxc-start 1390924308.607 E"..., 76) = 76

You didn't tell us which lxc version you are running.  There was a
period of time where ns cgroup support was missing.  If you switch to a
newer package it should be fixed.  Alternatively, make sure that the
ns nscgroup is not mounted.

-serge