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Description of problem: Per https://bugzilla.redhat.com/show_bug.cgi?id=988883 systemd-machined will often fail to remove cgroups during VM shutdown. This will then prevent libvirtd starting the VM again until the host is rebooted. This problem appears to affect LXC guests quite alot more than KVM guests, for reasons unknown. It will become a big problem for RHEL-7 when LXC error reporting is fixed per this bug https://bugzilla.redhat.com/show_bug.cgi?id=927072 The workaround is upstream already commit bd773e74f0d1d1b9ebbfcaa645178316b4f2265c Author: Cédric Bosdonnat <cbosdonnat> Date: Mon Sep 30 16:46:29 2013 +0200 LXC: workaround machined uncleaned data with containers running systemd. The problem is described by [0] but its effect on libvirt is that starting a container with a full distro running systemd after having stopped it simply fails. The container cleanup now calls the machined Terminate function to make sure that everything is in order for the next run. [0]: https://bugs.freedesktop.org/show_bug.cgi?id=68370 Version-Release number of selected component (if applicable): libvirt-1.1.1-8.el7 How reproducible: Random Steps to Reproduce: 1. virsh -c lxc:/// start guest 2. virsh -c lxc:/// destroy guest 3. goto step 1 Actual results: Eventually 'start' will fail with an error about cgroups (if you are lucky). Expected results: Additional info:
Hi Daniel , I still can't meet the error after downgrade the libvirt , systemd , kernel to previous version. libvirt-1.1.1-8.el7.x86_64 kernel-3.10.0-0.rc7.64.el7.x86_64 systemd-206-1.el7.x86_64 With the command , run 30 minutes # while true ; do virsh -c lxc:/// start test ; virsh -c lxc:/// destroy test ; done Does any other packages related to this issue else ? Or is there an effective way to reproduce the cgroup error with libvirt? Thanks .
(In reply to time.su from comment #3) > Hi Daniel , > > I still can't meet the error after downgrade the libvirt , systemd , kernel > to previous version. > > libvirt-1.1.1-8.el7.x86_64 > kernel-3.10.0-0.rc7.64.el7.x86_64 > systemd-206-1.el7.x86_64 > > With the command , run 30 minutes > # while true ; do virsh -c lxc:/// start test ; virsh -c lxc:/// destroy > test ; done > > > Does any other packages related to this issue else ? > Or is there an effective way to reproduce the cgroup error with libvirt? > Thanks . It turns out that the key thing is that you want to have systemd itself running inside the container. The best way to get this setup is to use libvirt-sandbox eg virt-sandbox-service create -u httpd.service myapache and then do your 'while true' loop using the 'myapache' guest.
Thanks your kindly help , Daniel. Verify this bug with libvirt-1.1.1-16.el7.x86_64 Steps: #virt-sandbox-service create -u httpd.service myapache #while true ; do virsh -c lxc:/// start myapache ; virsh -c lxc:/// destroy myapache ; done Expected:the container can be started and destroyed successfully In libvirt-1.1.1-8.el7.x86_64 The steps will cause 1.systemd crashed and generate core dump by abrtd 2.Libvirtd shows Assertion 'n_pids > 0' failed at src/shared/cgroup-show.c:47, function show_pid_array(). Aborting. Aborted (core dumped) 3.The container fail to start again due systemd has gone away.
This request was resolved in Red Hat Enterprise Linux 7.0. Contact your manager or support representative in case you have further questions about the request.