get running ceph-osd units

Must parse output from:

# systemctl list-units --state=running --type=service
UNIT LOAD ACTIVE SUB DESCRIPTION
accounts-daemon.service loaded active running Accounts Service
acpid.service loaded active running ACPI event daemon
atd.service loaded active running Deferred execution scheduler
ceph-osd@17.service loaded active running Ceph object storage daemon osd.17
cron.service loaded active running Regular background program processing daemon
dbus.service loaded active running D-Bus System Message Bus
getty@tty1.service loaded active running Getty on tty1
iscsid.service loaded active running iSCSI initiator daemon (iscsid)
lvm2-lvmetad.service loaded active running LVM2 metadata daemon
lxcfs.service loaded active running FUSE filesystem for LXC
mdadm.service loaded active running LSB: MD monitoring daemon
polkitd.service loaded active running Authenticate and Authorize Users to Run Privileged Tasks
rsyslog.service loaded active running System Logging Service
ssh.service loaded active running OpenBSD Secure Shell server
systemd-journald.service loaded active running Journal Service
systemd-logind.service loaded active running Login Service
systemd-timesyncd.service loaded active running Network Time Synchronization
systemd-udevd.service loaded active running udev Kernel Device Manager
user@1000.service loaded active running User Manager for UID 1000

LOAD = Reflects whether the unit definition was properly loaded.
ACTIVE = The high-level unit activation state, i.e. generalization of SUB.
SUB = The low-level unit activation state, values depend on unit type.

19 loaded units listed. Pass --all to see loaded but inactive units, too.
To show all installed unit files use 'systemctl list-unit-files'.