Libvirt Socket Binding Failed/Unable to Acquire PID File
Problem
The pf9-ostackhost service is failing, indicating that it is unable to connect to the Libvirt socket.
The libvirtd/libvirt-bin service is failing to start, complaining about being unable to access its pidfile.
Environment
Platform9 Managed OpenStack – v3.6 – v4.0
Nova
Libvirt 1.3.1
Ubuntu 16.04
Cause
Libvirtd is configured with the '-d' (daemon) option (set in /etc/default/libvirt-bin) which makes it unmanageable from a systemctl/systemd perspective – thus, attempting to start/restart the service will cause overlapping behavior, as a process is already started.
In order for the service to be properly managed – this flag should be unset.
Resolution
Kill any running Libvirt process(es).
Edit /etc/default/libvirt-bin and omit the '-d' flag from 'LIBVIRT_OPTS'.
Save the file.
Start the Libvirt service.
