Manually mounted directories in Ubuntu 15.04 containers are being immediately unmounted. Bind mounts, configured in the containers, are also affected.
The issue is known as a
systemd bug #1444402.
The bug was fixed in
systemd-219-7ubuntu6. To permanently resolve the issue, update
systemd package in affected containers by running the following command:
~# vzpkg update CT_ID
where CT_ID is the container ID.
In order to prevent the issue for newly created containers, update the template cache:
~# vzpkg update cache ubuntu-15.04-x86_64