HP StorageWorks XP48 - Disk Array, Owner'S Manual

Page: 104 / 124

104 HP SureStore E Disk Array XP512/XP48: Owner’s Guide
Figure 18. Data Reconstruction After Drive Error
There are two data integrity features built into the XP512: dynamic sparing
and correction copy. The XP512 uses spare disk drives and reconfigures
any drives that are blocked because of errors or whose error count exceeds
a specified limit value.
Since this processing is done in the background, the array can continue to
accept host I/O requests. The data saved on spare disks is copied back into
the original location after the drive with errors has been replaced with a
new one.
DKC
(RAID5)
M8 D6 D8 M6
M7 D5 D7 M5
M4 D2 D4 M2
M3 D1 D3 M1
P
(10-12)
D11 D10 D12
P
(7-9)
D7 D9 D8
P
(4-6)
D6 D5 D4
P
(1-3)
D1 D2 D3
DKC
RAID 0/1
D2
Disk 1 Disk 2 Disk 3 Disk 4 Disk 1 Disk 2 Disk 3 Disk 4
D1 D3 P
(1-3)
HOST
D2
HOST
D2