Warning: Please make a backup before following any advise given here :-)
ARRAY /dev/md1 level=raid0 num-devices=2 UUID=d89d9d45:9a420812:c44c77eb:7ee19756 devices=/dev/sdb8,/dev/sda8
I just entered your own output and changed 127 to 1. Reboot and it should be md1 now.
If you don't have
mdadm.conf, and want it to assemble to md1 automagically, you can do this:
mdadm has a concept of a "preferred minor". E.g. once a certain minor number is assigned to an array, and stored in the superblock, it will be used each time this array is auto-assembled. Verify this:
mdadm --detail /dev/md127
If it says "Preferred Minor : 127" this this is your problem. You need to update the preferred minor. How to do this:
You cannot just change the preferred minor. You need to boot into recovery or single user-mode if this is your root device, unmount the filesystem, after that:
mdadm --stop /dev/md127
mdadm --assemble --update=super-minor /dev/md1 /dev/sdb8 /dev/sda8
Then you'll have your md127 assembled as md1. And it should stay this way in the future too.