Raid 5 And 50 - HP 3PAR StoreServ 7200 2-node Manual

Figure 4 Data Striped Across RAID 1 Sets on a RAID 10 Logical Disk

RAID 5 and 50

On a RAID 50 logical disk, data is striped across rows of RAID 5 sets. A RAID 5 set, or parity set,
must contain at least three chunklets. A RAID 5 set with three chunklets has a total of two chunklets
of space for data and one chunklet of space for parity. RAID 5 set sizes with between 3 and 9
chunklets are supported. The data and parity steps are striped across each chunklet in the set. The
chunklets in each RAID 5 set are distributed across different physical disks, which may be located
in different drive magazines or even different drive cages. The number of sets in a row is the row
size. The system accesses the data from a RAID 50 logical disk in step sizes. The step size is the
number of contiguous bytes that the system accesses before moving on to the next chunklet. A RAID
5 set can function with the loss of any one of the chunklets in the set.
Figure 5 (page 37)
36 Logical Disks
shows a RAID 50 logical disk with a set size of 3, and 2 sets in 1 row: