[libvirt] Loosing lxc guests when restarting libvirt

Hi, I found an issue in libvirt related to libvirt-lxc, but fail to find the root cause. The TL;DR is: libvirt-lxc guests get killed on libvirt restart due to "internal error: No valid cgroup for machine" It was able to reproduce libvirt 1.3.1, 2.4 and 2.5 as packages in Ubuntu and Debian. I wanted to ask for two things: - wider coverage where this does reproduce - your expertise on the case itself. Steps to reproduce: 1. Spawn new KVM Guest of your choice 2. install test dependencies $ apt-get install libvirt-daemon-system libvirt-clients libxml2-utils # or package managers / package names of your chosen os 3. run the following sequence as root export LIBVIRT_DEFAULT_URI=lxc:/// cat << EOF > /tmp/smoke-lxc.xml <domain type='lxc'> <name>sl</name> <memory unit='KiB'>256000</memory> <currentMemory unit='KiB'>256000</currentMemory> <vcpu placement='static'>1</vcpu> <os> <type>exe</type> <init>/bin/bash</init> </os> <features> <privnet/> </features> <clock offset='utc'/> <devices> <emulator>/usr/lib/libvirt/libvirt_lxc</emulator> <filesystem type='mount' accessmode='passthrough'> <source dir='/'/> <target dir='/'/> </filesystem> <console type='pty'> <target type='lxc' port='0'/> </console> </devices> </domain> EOF virsh define /tmp/smoke-lxc.xml virsh start sl virsh list --all # is running now /etc/init.d/libvirtd restart virsh list --all # is no more running, but it should Way more background and detail can be found at https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=848317 -- Christian Ehrhardt Software Engineer, Ubuntu Server Canonical Ltd