$ journalctl _COMM=lvmetad|tail -2
-- Reboot --
sept. 05 09:26:18 data-dev4 lvmetad[372]: Cannot lock lockfile [/run/lvmetad.pid], error was [Resource temporarily unavailable]


$ ps -aux|grep l[v]m
root        60  0.0  0.0 160440   444 ?        Ssl  09:26   0:00 lvmetad
root       117  0.0  0.0  25924  5064 ?        Ss   09:26   0:00 (lvm2)       pvscan --background --cache --activate ay --major 8 --minor 21
root       355  0.0  0.0  27280  3832 ?        Ss   09:26   0:00 /usr/bin/lvm pvscan --cache --activate ay 8:5
root       423  0.0  0.0  27280  3692 ?        Ss   09:26   0:00 /usr/bin/lvm pvscan --cache --activate ay 8:21
$ for i in 60 117 355 423 ; do ps -o lstart= -p $i ; done
Fri Sep  5 09:26:15 2014
Fri Sep  5 09:26:16 2014
Fri Sep  5 09:26:18 2014
Fri Sep  5 09:26:20 2014


$ cat /usr/lib/systemd/system/lvm2-lvmetad.service
[Unit]
Description=LVM2 metadata daemon
Documentation=man:lvmetad(8)
Requires=lvm2-lvmetad.socket
After=lvm2-lvmetad.socket
DefaultDependencies=no
Conflicts=shutdown.target

[Service]
Type=simple
NonBlocking=true
ExecStart=/usr/bin/lvmetad -f
Environment=SD_ACTIVATION=1
Restart=on-abort
PIDFile=/run/lvmetad.pid

[Install]
WantedBy=sysinit.target