HP A7143A RAID160 SA Controller Support Guide

Hard Drive Installation and Replacement
Drive Failure During Rebuild
Appendix C 151
Do not remove a second drive from an array until the first failed or
missing drive has been replaced and the rebuild process is complete.
(When the rebuild is complete, the Online LED on the front of the
drive stops blinking.)
There are some exceptions:
In RAID ADG configurations, any two drives in the array can be
replaced simultaneously.
In RAID 1+0 configurations, any drives that are not mirrored to
other removed or failed drives can be simultaneously replaced
offline without data loss.