The server (Debian) was moved from 32 to 64 bits. The process took one day of downtime for the add-on and is not over yet. The host switched to kernel 2.6.32-openvz-042stab108.2-amd64 along with amd64 userspace. All the VEs still are 32 bit and need conversion.
I also had a taste of the "new & cool" systemd of Debian 8 while considering an upgrade from the current Debian 7 installed on the host. After 7 years of having used exclusively Debian on all my computers, the decision I took is simple: I will never upgrade Debian above release 7 if systemd will break the balls. Rather, I will wait for the APIs and standards to diverge to the point where Debian 7 will become the equivalent modern trashware of the Commodore C64, and move along after.