I got a similar problem on a configuration with raid5 and lvm. Since the upgrade to 3.3.4-1.1 my computer refused to boot.
The configuration is: 3 HDD in raid 5: /dev/sdb1, /dev/sdc1, /dev/sdd1 -> /dev/md127 one LVM physical volume with one volume group declared on the raid device. several LVM logical volumes declared on the volume group /home partition in one of these physical volumes. When booting, the machine was stuck waiting for /home and finally falled back to asking me root password on a console. The LVM volumes did not appear in /dev/mapper at this stage. I was able to continue booting by running systemctl restart mdadm-raid the result was a correct activation of LVM and mounting of the partition, depite I get an error message in the systemctl command (I don't remember the message).
