Tom Allison wrote, On 2-Sep-2008 21:12:
I'm going to sound dumb, but isn't that just marking it bootable and then running grub on the second disk to set the grup boot files in place on the second disk?
Yes,Gentoo has a good tutorial in its wiki. I used that as there are some 'special' things for the second disk (since it will be primary when booting from it).
It will protect you when the first disk fails and is removed. I did some hot-plugging tests to make sure it worked.
I have never tested whether the system will actually start when the first disk gets a corrupted boot sector. This seems extremely unlikely though. Better possible seems a corrupted boot partition, but RAID1 can, in principle, recover from this after the failure.
- Joris