Moving Fedora 22 to RAID 0 - Trouble with initramfs

[Samuel Rakitničan]

I have moved / partition to another partition formed in RAID 0
consisting of two SSDs. I have updated fstab with new partition UUID,
reinstalled GRUB2 and rebuild initramfs using dracut -f. Now computer
boots fine from RAID partition but hangs on when initramfs needs to
boot kernel from / partition found on RAID, because it can't find
partition with UUID that I've put in fstab.

Now from what I have understood when it drops me to dracut prompt in
initramfs boot process I indeed can't find the RAID assembled BUT I
can assemble it manually by using "mdadm -I /dev/sda" and "mdadm -I
/dev/sdb". If I boot from old hard drive the RAID is assembled
normally in kernel on boot time:

$ journalctl -b | grep "kernel: md"

Kol 30 01:20:53 computername kernel: md: bind<sdb>
Kol 30 01:20:53 computername kernel: md: bind<sda>
Kol 30 01:20:53 computername kernel: md: bind<sdb>
Kol 30 01:20:53 computername kernel: md: bind<sda>
Kol 30 01:20:53 computername kernel: md: raid0 personality registered
for level 0
Kol 30 01:20:53 computername kernel: md/raid0:md126: md_size is
500129792 sectors.
Kol 30 01:20:53 computername kernel: md: RAID0 configuration for md126 - 1 zone
Kol 30 01:20:53 computername kernel: md: zone0=[sda/sdb]
Kol 30 01:20:53 computername kernel:       zone-offset=         0KB,
device-offset=         0KB,
Kol 30 01:20:53 computername kernel:
Kol 30 01:20:53 computername kernel: md126: detected capacity change
from 0 to 256066453504
Kol 30 01:20:53 computername kernel:  md126: p1 p2 p3
Kol 30 01:20:53 computername kernel: md: export_rdev(sdb)
Kol 30 01:20:53 computername kernel: md: export_rdev(sda)
Kol 30 01:20:53 computername kernel: md: export_rdev(sdb)
Kol 30 01:20:53 computername kernel: md: export_rdev(sda)


The RAID is formed using onboard southbridge Intel controller. I have
managed to extract data from initramfs but I am not sure what to look
for, in particular what brings up RAID assembly.
/etc/udev/rules.d/65-md-incremental-imsm.rules seems like it's
responsible to assemble, but I am not sure.

Any thoughts why imsm RAID is not assembled in initramfs on boot?