24.8 RAID Hot Spares
Regarding the example, the slide shows...
sudo mdadm --create /dev/md0 -l 5 -n3 -x 1 /dev/sda8 /dev/sda9 /dev/sda10 /dev/sda11
Then to test...
sudo mdadm --fail /dev/md0 /dev/sdb2
It says that this would test the redundancy and hot spare of the array.
Shouldn't the device be from what was used to define md0?
Like sda8, sda9, sda10, or sda11?
How is /dev/sdb2 factored into /dev/md0?