HP 3PAR StoreServ Concepts Guide: HP 3PAR OS 3.1.3

Figure 6 Data Striped Across RAID 1 Sets on a RAID 10 LD
RAID 5 and RAID 50
On a RAID 50 LD, 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 LD 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 7 (page 39) shows a RAID 50 LD with a set size of 3, and 2 sets in 1 row:
38 LDs