Unable to connect to libvirt.

Verify that the 'libvirtd' daemon is running.

Libvirt URI is: qemu:///system

Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/connection.py", line 904, in _do_open
    self._backend.open(self._do_creds_password)
  File "/usr/share/virt-manager/virtinst/connection.py", line 148, in open
    open_flags)
  File "/usr/lib/python2.7/site-packages/libvirt.py", line 105, in openAuth
    if ret is None:raise libvirtError('virConnectOpenAuth() failed')
libvirtError: Failed to connect socket to '/var/run/libvirt/libvirt-sock': No such file or directory