Currently Being ModeratedNov 9, 2012 4:25 AM (in response to eliotic)
I've never used Apple RAID but I would think if you remove the second drive and then run the system it will know the second drive is gone. You may need to delete the partition on the new second drive before it will do a successful RAID rebuild.
That said wouldn't it be simpler to use Carbon Copy Cloner to make an image of your system to the third drive. I recommend at least two backup drives because at the instant you start a clone to a single drive you have no backup drive until the clone process is completed.
Currently Being ModeratedNov 9, 2012 12:27 PM (in response to eliotic)
if you remove a drive from a RAID1 set, it will not just start copying the contents to a new drive that you pop in.
it will do nothing. The RAID set will just assume theyre separated and wait for you to put them both online again.