21.2 RAID 1 Logical Drives

A RAID 1 logical drive is built from two disk drives, where one disk drive is a mirror of the other (the same data is stored on each disk drive). Compared to independent disk drives, RAID 1 logical drives provide improved performance, with up to twice the read rate and an equal write rate of single disks. However, capacity is only 50 percent of independent disk drives.

If the RAID 1 logical drive is built from different- sized disk drives, the free space, drive segment size is the size of the smaller disk drive, as shown in this figure.