[Pkg-libvirt-maintainers] Bug#761521: Bug#761521: libvirt-daemon: fails to restart domain with error 'CreateMachine: File exists'

[Paul Millar]

Hi,

On 16/09/14 09:16, Guido Günther wrote:
> However VMs create a machine.slice here:
>
> ./cpuset/machine.slice/machine-qemu\x2d<machinename>.scope/
>
> Could you check if this gets properly removed when you shut down the domain?
> Cheers,

I have a couple of bits of information that could prove useful.

In /etc/libvirt/qemu.conf I have the line:

     user = "paul"

If I comment out this line and restart the machine then the qemu process 
runs as user "libvirt+" and the problem goes away.


Second, I've found a work-around for the problem, which is to run (as 
user paul) the following command:

     kill $(cat 
/sys/fs/cgroup/systemd/machine.slice/machine-qemu\\x2dxanadu.scope/tasks)

After this, the machine.slice directory no longer contains a 
machine-qemu\\x2xanadu.scope directory.

The 'tasks' file contains four pids, two of which are active after the 
domain has shut down.  These still-running processes are:

     /usr/bin/pulseaudio --start --log-target=syslog

and

     /usr/lib/pulseaudio/pulse/gconf-helper

Before starting the domain, I have a pulseaudio and gconf-helper 
processes running.  After starting the domain, I have two pulseaudio and 
two gconf-helper processes.

When I remove the user="paul" line from qemu.conf (so qemu runs as user 
"libvirt+") no additional pulseaudio or gconf-helper processes are 
started when starting the domain.

Therefore, it looks like the problem is caused by additional 
pulseaudio/gconf-helper processes mistakenly created, or the process 
responsible for killing them when the domain shuts down is unable to do 
so or fails to receive the notification.

HTH,

Paul