Comment 29 for bug 1571209

My Trusty system wan't as slow, so I used 100 guests on autostart.

But that seemed to work as well (test adapted for upstart):

./test-restart.sh
+ date
Wed Sep 6 09:34:58 UTC 2017
+ sudo service libvirt-bin start
libvirt-bin start/running, process 19805
+ date
Wed Sep 6 09:35:00 UTC 2017
+ /bin/true
+ ls -laF /var/run/libvirt/libvirt-sock
srwxrwx--- 1 root libvirtd 0 Sep 6 09:34 /var/run/libvirt/libvirt-sock=
+ sudo service libvirt-bin status
libvirt-bin start/running, process 19805
+ ls -laF /var/run/libvirt/libvirt-sock
srwxrwx--- 1 root libvirtd 0 Sep 6 09:34 /var/run/libvirt/libvirt-sock=
+ virsh list

So the socket is immediately available even with all sorts of slow guests starting.
Unfortunately the initial bug 1455608 wasn't too detailed on an actual case.
Actually I'd have refused that as a SRU team member :-/

Well live with what we have.
For now I'll try to slow more things down and recheck.