mdadm doesn’t record the raid settings automatically, after you set everything up, you have to remember to save the mdadm.conf file.
Anyway, I forgot to do that, and on reboot, it hung my machine
So here is how I recovered it.
originally, my stripe was created with:
and so I was able to recreate the stripe using:
and then mount it with:
so then I saved the /etc/mdadm.conf file with:
mdadm –detail –scan >> /etc/mdadm.conf
So before adding it back into my /etc/fstab, I reboot, and check that I can mount it
and if that works (it did), I add back into /etc/fstab
and reboot again.