The "/usr appears to be on its own filesystem ..." is just a warning. Booting with separate /usr is supported, as long as it's a local partition and not a remote one (the latter could work, but really nobody tests this). I just did a 15.04 installation with separate /usr, and it works fine.
Could there be something wrong with your /etc/fstab perhaps? Maybe some UUID mismatch or so? In the emergency shell, can you please do journalctl -b > /root/journal.txt blkid > /root/blkid.txt and attach /etc/fstab, /root/blkid.txt, and /root/journal.txt here? Thanks! ** Summary changed: - systemd will not work with a separate /usr partition + systemd does not boot with a separate /usr partition ** Changed in: systemd (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1460794 Title: systemd does not boot with a separate /usr partition To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1460794/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs