HP 3PAR StoreServ Concepts Guide: HP 3PAR OS 3.1.3
Figure 7 Data Striped Across RAID 5 Sets on a RAID 50 LD
RAID MP or RAID 6
On a RAID MP or RAID 6 LD, data is striped across rows of RAID MP sets. A RAID MP set, or
double-parity set, must contain at least 8 chunklets. A RAID MP set with eight chunklets has a total
of six chunklets of space for data and two chunklets of space for parity. RAID MP set sizes of eight
and 16 chunklets are supported. The data and parity steps are striped across each chunklet in the
set. The chunklets in each RAID MP 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 MP LD in step sizes. The step size varies
and is dependent on the size of the RAID MP set. A RAID MP set can function with the loss of any
two of the chunklets in the set.
The following example shows 2 RAID MP sets in one row, the second set is shown below the first
set. In the first RAID MP set in the following example, p0 is the parity step for data steps F, L, M,
Q, T, V, and X. Figure 8 (page 40) shows a RAID MP LD with a set size of 8, and 2 sets in 1 row:
RAID Types 39