With cgroup v1 I'm seeing LXC container startup failures: $ sudo virt-install --connect lxc:/// --name test-container --memory 128 --boot init=/bin/sh Starting install... ERROR error from service: GDBus.Error:org.freedesktop.machine1.NoMachineForPID: PID 2145047 does not belong to any known machine libvirt 7.0.0 works but 7.1.0+ does not. The root error seems to predate that, showing up in syslog, but commit 9c1693eff made it fatal: commit 9c1693eff427661616ce1bd2795688f87288a412 Author: Pavel Hrdina <phrdina(a)redhat.com&gt; Date: Fri Feb 5 16:17:35 2021 +0100 vircgroup: use DBus call to systemd for some APIs The error comes from virSystemdGetMachineByPID. The PID that shows up in the above error message does not match the leader PID as reported by machinectl. This change fixes the error. Things seem to continue to work with cgroupsv2 after this change. https://gitlab.com/libvirt/libvirt/-/issues/182 Signed-off-by: Cole Robinson <crobinso(a)redhat.com&gt; --- This is from the thread in August, posted as non RFC now src/lxc/lxc_controller.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/lxc/lxc_controller.c b/src/lxc/lxc_controller.c index 8953e0c904..444f728af4 100644 --- a/src/lxc/lxc_controller.c +++ b/src/lxc/lxc_controller.c @@ -865,12 +865,12 @@ static int virLXCControllerSetupCgroupLimits(virLXCController *ctrl) nodeset = virDomainNumatuneGetNodeset(ctrl->def->numa, auto_nodeset, -1); if (!(ctrl->cgroup = virLXCCgroupCreate(ctrl->def, - ctrl->initpid, + getpid(), ctrl->nnicindexes, ctrl->nicindexes))) goto cleanup; - if (virCgroupAddMachineProcess(ctrl->cgroup, getpid()) < 0) + if (virCgroupAddMachineProcess(ctrl->cgroup, ctrl->initpid) < 0) goto cleanup; /* Add all qemu-nbd tasks to the cgroup */ -- 2.31.1