HP XP P9500 Storage - Manual (Page 17)

Table 3 Volume Information for BC
Associated L2
P-VOL AssociatedL2
S-VOLs Associated L1
P-VOLs Associated L1
S-VOLs Pair Volume
Type GID: LUN Port CU
NA NA NA 1B-0:00,
2A-0:00,
2B-0:00 L1 P-VOL 0:00 1A 0
NA NA NA 1B-0:01,
2A-0:01,
2B-0:01 L1 P-VOL 0:01 1A 0
NA NA NA NA NA NA NA etc...
NA 3A-0:00,
3A-0:01 1A-0:00 NA L1 S-VOL
L2 P-VOL
0:00 1B 0
NA 3B-0:00, 3B-0:01 1A-0:00 NA L1 S-VOL 0:01 1B 0
L2 P-VOL
NA NA NA NA NA NA NA etc...
NA 4A-0:00, 3B-0:01 1A-0:00 NA L1 S-VOL 0:00 2A 0
L2 P-VOL
NA 4B-0:00, 3B-0:01 1A-0:00 NA L1 S-VOL 0:01 2A 0
L2 P-VOL
NA NA NA NA NA NA NA etc...
1B-0:00 NA NA NA L2 S-VOL 0:00 3A 0
1B-0:00 NA NA NA L2 S-VOL 0:01 3A 0
Planning for performance
Pair operations affect I/O performance on the storage system. The following information is provided
to help calibrate your system:
•
Performance versus number of pairs. Compare the importance of performance with the number
of pairs and copy pace (rate at which data is copied).
◦ Assigning multiple S-VOLs to a P-VOL uses more system resources and lowers performance.
◦ The slower the copy pace, the less impact on I/O performance; a fast pace has a greater
impact on performance. (You assign copy pace while creating, splitting, and
resynchronizing pairs.)
•
Load sharing on parity groups.
A parity group should contain an even distribution of P-VOLs and S-VOLs, rather than a
concentration of one or the other.
◦
◦ If you plan to perform multiple pair operations simultaneously, place the pairs in different
parity groups.
◦ For copy pace, specify Slower when you create, split, or resynchronize.
◦
If you plan to perform a copy operation on multiple pairs on the same parity group,
perform the operation on one pair at a time.
◦ If the system is overloaded, increase parity groups, cache, channel adapters (CHAs),
and/or disk adapters (DKAs). Assign S-VOLs to newly installed parity groups.
Planning for performance 17