ubuntu@rack3-ceph-controller:~$ df -h
Filesystem                 Size  Used Avail Use% Mounted on
udev                        16G     0   16G   0% /dev
tmpfs                      3.2G  9.1M  3.2G   1% /run
/dev/mapper/vgroot-root     28G  7.2G   19G  28% /
/dev/vgroot/usr             46G 1020M   43G   3% /usr
tmpfs                       16G     0   16G   0% /dev/shm
tmpfs                      5.0M     0  5.0M   0% /run/lock
tmpfs                       16G     0   16G   0% /sys/fs/cgroup
/dev/mapper/vgroot-home     92G   60M   87G   1% /home
/dev/mapper/vgroot-boot    922M   57M  802M   7% /boot
/dev/mapper/vgroot-var      28G  601M   26G   3% /var
/dev/sda1                  511M  3.6M  508M   1% /boot/efi
/dev/mapper/vgroot-varlog   28G   46M   26G   1% /var/log
tmpfs                      3.2G     0  3.2G   0% /run/user/1000

ubuntu@rack3-ceph-controller:~$ sudo systemctl --all
● jujud-machine-1.service     not-found inactive dead      jujud-machine-1.service
● jujud-unit-ceph-mon-1.service   not-found inactive dead      jujud-unit-ceph-mon-1.service

ubuntu@rack3-ceph-controller:~$ sudo systemctl start jujud-machine-1.service
Failed to start jujud-machine-1.service: Unit jujud-machine-1.service not found.

ubuntu@rack3-ceph-controller:~$ sudo systemctl start jujud-unit-ceph-mon-1.service
Failed to start jujud-unit-ceph-mon-1.service: Unit jujud-unit-ceph-mon-1.service not found.

// Reloading Systemd daemon loads the Juju services back in
ubuntu@rack3-ceph-controller:~$ sudo systemctl daemon-reload