HP Smart Storage Administrator - Manual (Page 110)

Troubleshooting 110
RAID 1 and RAID 1+0 (RAID 10)
In RAID 1 and RAID 1+0 (RAID 10) configurations, data is duplicated to a second drive.
When the array contains only two physical drives, the fault-tolerance method is known as RAID 1.
When the array has more than two physical drives, drives are mirrored in pairs, and the fault-tolerance
method is known as RAID 1+0 or RAID 10.
In each mirrored pair, the physical drive that is not busy answering other requests answers any read requests
that are sent to the array. This behavior is called load balancing. If a physical drive fails, the remaining drive
in the mirrored pair can still provide all the necessary data. Several drives in the array can fail without
incurring data loss, as long as no two failed drives belong to the same mirrored pair.
This fault-tolerance method is useful when high performance and data protection are more important than the
cost of physical drives.
Advantages:
• This method has the second highest read performance of any fault-tolerant configuration.