Dracut is unable to mount /usr if on separate partition, because it adds double quotes to the initramfs fstab: mount: special device /dev/disk-by-uuid/"041af...." does not exist. The same error also appears during boot. The system is able to mount / of course, but it fails anything else, because it adds quotes in the access path.
*** This bug has been marked as a duplicate of bug 555856 ***