After upgrading a VE to Jaunty through do-release-upgrade, the network stopped working.

A post in the OpenVZ forum suggests a fix that works for me:

On the host:

vzctl set XXX --features "sysfs:on" --save

In the container:

vi /etc/init.d/networking

After the comments at the top, add the line:

mkdir -p /var/run/network

Note the post suggested the directory var/run/networking, my init script wanted /var/run/network for some reason. I also added -p to mkdir.

Presumably, there’s a smoother solution creating the directory through the OpenVZ init scripts.

Update: Here’s a more detailed explanation of what’s going on.

Another problem I had was klogd hanging and preventing the boot process from finishing. The only solution seems to be to remove klogd from autostart (update-rc.d -f remove klogd) [1] [2].