The Block Storage service (openstack-cinder-volumes) is initialized earlier in the boot process than items listed in the rc.local file.
On systems deployed by PackStack and configured to use a volume group backed by loopback device for block storage this meant that the volume group was not available when the Block Storage service was started on boot. As a result the service would fail to start.
PackStack has been updated and now ensures that the Block Storage service is restarted once the rc.local file is processed and the volume group is available. This ensures that the Block Storage service continues to function correctly following reboot.