[libvirt-users] lxc containers won't start in a f24 custom install - odd cgroup fs layout observed

Hi folks I use libvirt to programmatically spawn lxc containers I am facing an issue when migrating from fedora23 to fedora24 I use the stock kernel and libvirt version on both deployments, i.e.: f23: libvirt-1.2.18.3-2.fc23.x86_64 - kernel 4.5.7-202.fc23.x86_64 f24: libvirt-1.3.3.1-4.fc24.x86_64 - kernel 4.6.3-300.fc24.x86_64 First off, I need to outline that the host installation is done through some ad hoc procedure, as all this happens in the context of the centrally-managed PlanetLab global infrastructure I could not reproduce this problem on a host that is installed with the standard fedora install However I could use any clue that would point at a possible reason for this IMHO odd behaviour from libvirt, so that I can narrow down the potential flaws in my host installation procedure At first sight, it looks like the f24 deployment uses a different cgroup fs layout - see below and I suspect this could be the problem, but I am not aware of anything in my install. procedure that could cause that change, and as per this document https://libvirt.org/cgroups.html#systemdScope this change in the naming scheme looks odd - unless the doc is out of date of course So again, any clue is most welcome; many thanks in advance -- Thierry ------ All is fine with f23/libvirt-1.2.18.3-2.fc23.x86_64 However with f24/libvirt-1.3.3.1-4.fc24.x86_64 my lxc containers won't start and I am seeing this message in the libvirtd logfile 2016-07-09 11:52:33.416+0000: 3479: debug : virCgroupValidateMachineGroup:317 : Name 'lxc-3555-inrisl1.libvirt-lxc' for controller 'cpu' does not match 'inri_sl1', 'lxc-3555-inrisl1', 'inri_sl1.libvirt-lxc', '\ machine-lxc\x2dinri_sl1.scope' or 'machine-lxc\x2d3555\x2dinrisl1.scope' 2016-07-09 11:52:33.416+0000: 3479: debug : virCgroupNewDetectMachine:1501 : Failed to validate machine name for 'inri_sl1' driver 'lxc' 2016-07-09 11:52:33.416+0000: 3479: error : virLXCProcessStart:1501 : internal error: No valid cgroup for machine inri_sl1 At first it looked like the issue could be linked to the domain name having an underscore (example below uses inri_sl1 as a domain name) But trying with a regular name 'plain' without an underscore exhibits a similar issue ------------------------- Here's the set of files under /sys/fs/cgroup/memory that contains 'inri' in their name (other susbsytems have similar naming schemes in both cases) ========= f23 / libvirt-1.2.18.3-2.fc23.x86_64 (works fine) [root@vnode06 log]# cat /etc/fedora-release Fedora release 23 (Twenty Three) [root@vnode06 log]# uname -r 4.5.7-202.fc23.x86_64 [root@vnode06 log]# rpm -q libvirt libvirt-1.2.18.3-2.fc23.x86_64 [root@vnode06 log]# find /sys/fs/cgroup/memory/ -name '*inri*' /sys/fs/cgroup/memory/machine.slice/machine-lxc\x2dinri_sl1.scope ========= f24 / libvirt-1.3.3.1-4.fc24.x86_64 (container won't start) [root@vnode05 libvirt]# cat /etc/fedora-release Fedora release 24 (Twenty Four) [root@vnode05 libvirt]# uname -r 4.6.3-300.fc24.x86_64 [root@vnode05 libvirt]# rpm -q libvirt libvirt-1.3.3.1-4.fc24.x86_64 [root@vnode05 libvirt]# find /sys/fs/cgroup/memory/ -name '*inri*' /sys/fs/cgroup/memory/machine/lxc-3237-inrisl1.libvirt-lxc /sys/fs/cgroup/memory/machine/lxc-3555-inrisl1.libvirt-lxc /sys/fs/cgroup/memory/machine/lxc-2989-inrisl1.libvirt-lxc