ok ran into an issue.
i don't have md0/md1, i have md1/md2. so i figured md1=md0 and md2=md1 from your examples. they use the same sda1/sdb1 set up as what you showed. here's my mdstat:
root@:/# cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] [multipath] [faulty]
md1 : active raid1 sdb1[1] sda1[0]
5245120 blocks [2/2] [UU]
md2 : active raid1 sdb2[1] sda2[0]
726804608 blocks [2/2] [UU]
unused devices:
so i did:
mdadm -f /dev/md1 /dev/sdb1
mdadm -r /dev/md1 /dev/sdb1
which worked fine. formatted, and mounted. but capacity is only 40mb or something???
i undid my changes and remounted it as a raid array which has already completed rebuilding. don't want to screw it up, what am i doing wrong?