libvirt users - May 2019 - VM bootup got failed with systemd/dbus error messages

We are having one server machine (ubuntu 16.04 OS) with 10 VMs.

When the server is rebooted, some VMs got failed to boot with systemd/dbus
error messages.
Rebooting the affected VMs resolves this issue.

Jan 30 20:40:02 VM systemd[1]: Failed to subscribe to NameOwnerChanged
signal for 'org.freedesktop.DisplayManager': Connection timed out
Jan 30 20:40:02 VM systemd[1]: Failed to subscribe to NameOwnerChanged
signal for 'org.freedesktop.NetworkManager': Connection timed out
Jan 30 20:40:02 VM systemd[1]: Failed to subscribe to NameOwnerChanged
signal for 'org.freedesktop.login1': Connection timed out
Jan 30 20:40:02 VM systemd[1]: Failed to subscribe to NameOwnerChanged
signal for 'org.freedesktop.Accounts': Connection timed out
Jan 30 20:40:02 VM systemd[1]: Failed to subscribe to NameOwnerChanged
signal for 'org.freedesktop.Avahi': Connection timed out
Jan 30 20:40:02 VM systemd[1]: Failed to subscribe to NameOwnerChanged
signal for 'org.freedesktop.ModemManager1': Connection timed out
Jan 30 20:40:02 VM systemd[1]: Failed to subscribe to activation signal:
Connection timed out
Jan 30 20:40:02 VM systemd[1]: Failed to register name: Connection timed out
Jan 30 20:40:02 VM systemd[1]: Failed to set up API bus: Connection timed
out

an 30 20:40:32 VM dbus[1009]: [system] Failed to activate service
'org.freedesktop.systemd1': timed out
Jan 30 20:40:32 VM systemd-logind[998]: Failed to enable subscription:
Failed to activate service 'org.freedesktop.systemd1': timed out
Jan 30 20:40:32 VM systemd-logind[998]: Failed to fully start up daemon:
Connection timed out

Host machine specifications:-
OS        : Ubuntu 16.04
Kernel  : 4.15.0-47-generic
CPUs   : 48 ( 2*12*2)
RAM    : 64G

VM specifications:-
OS        : Ubuntu 16.04
Kernel  : 4.13.16
CPUs   : 8
RAM    : 4G

Attached the full log file.
Kindly help us to resolve this issue with a permanent fix.

*With Best Regards,*

M A PRIYANKA

VVDN Technologies Pvt Ltd

*Cell : * +91 8489574081 | *Skype :* priyankamathavan27

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