I hit this behavior too.
I upgraded 14.04 on test laptop to 15.04 and it worked ok , but after last
update system missing /sbin/init and won't boot.
before rebooted I tried to issue init command and get message the /sbin/init
provided by upstart (systemd was not refenced)
also searching for init
multiple simultaneous VPN connections is a pretty basic feature of any desktop
OS including Windows so it is a MUST for Linux and not a "wish list"
Most people requesting this feature talking about the same - supporting
multiple customers and I join their voice as it is my basic everyday need:
S