Well, your RAID issues are not really related to UCS. It’s a basic issue.
But to prevent UCS to fail during boot when the RAID is not available you should add and option to your /etc/fstab
Before (example):
/dev/md127 /mnt defaults ext4 0 0
use
/dev/md127 /mnt defaults,errors=continue ext4 0 0
In this case the UCS will start fine even when your RAID is not available. Then you can loging as usual and do troubleshooting why the RAID failed.
/KNEBB