libvirt users - Feb 2014 - Re: libvirt lxc /dev/null

Hello,

I created lxc container on F19 with virt-manager and it starts OK. The only
problem is that sshd does not run complaining "/dev/null is not a character
device".
# ls -l /dev/null
-rw-r--r-- 1 root root 0 2014-02-25 22:39 /dev/null

/sys/fs/cgroup/devices/machine/VM_NAME.libvirt-lxc/devices.list has "c 1:3
rwm" line, but I cannot create /dev/null:
# mknod /dev/nulll c 1 3
mknod: `/dev/nulll': Operation not permitted

Thanks,
Nerijus

On Tue, Feb 25, 2014 at 08:58:43PM +0000, Nerijus Baliunas
wrote:
> Hello,
> 
> I created lxc container on F19 with virt-manager and it starts OK. The only
> problem is that sshd does not run complaining "/dev/null is not a
character
> device".
> # ls -l /dev/null
> -rw-r--r-- 1 root root 0 2014-02-25 22:39 /dev/null
> 
> /sys/fs/cgroup/devices/machine/VM_NAME.libvirt-lxc/devices.list has "c
1:3
> rwm" line, but I cannot create /dev/null:
> # mknod /dev/nulll c 1 3
> mknod: `/dev/nulll': Operation not permitted
Libvirt will pre-populate the /dev filesystem with any permitted
devices, creation is denied by cgroups.

That you have a plain file for /dev/null suggests something in
your container has deleted the original character device and
replaced it by a plain file.

Regards,
Daniel
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Daniel P. Berrange <berrange@...> writes:
> Libvirt will pre-populate the /dev filesystem with any permitted
> devices, creation is denied by cgroups.
> 
> That you have a plain file for /dev/null suggests something in
> your container has deleted the original character device and
> replaced it by a plain file.
Thank you. I removed udev package in the container and now /dev/null is OK.

Regards,
Nerijus