Comment # 5 on bug 923150 from Neil Brown

Once the mdraid devices start, which they clearly do, the lvm devices should be
automatically started by the line

ENV{ID_FS_TYPE}=="LVM2_member|LVM1_member", RUN+="/sbin/lvm pvscan --cache
--activate ay --major $major --minor $minor"

in

/usr/lib/udev/rules.d/69-dm-lvm-metad.rules


Maybe lvmetad isn't running... That seems to be needed for that command to
work,
and possibly it isn't by default.

Please edit /etc/lvm/lvm.conf and if there is a line like:

    use_lvmetad = 0

change it to

    use_lvmetad = 1

Also run
   systemctl enable lvmetad.socket

Then reboot and report the results.