HP XP Business Copy Software - Manual (Page 48)

Performance Considerations
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When you operate XP Business Copy:
XP Business Copy operations affect the I/O performance of the storage system because of the
copy operations to the S-VOLs. You should consider the relative importance of the storage
system’s I/O performance and the XP Business Copy operations when you decide the number
or structures of pairs and their copy pace.
For example, assigning three S-VOLs to each P-VOL takes more resources than assigning only
one or two. The more S-VOLs you assign to a P-VOL, the larger the attenuating effect on the
potential P-VOL I/O performance.
If you assign one S-VOL on a P-VOL, the pace of the initial copy operations may affect the
I/O performance of the storage system. Using a slower copy pace minimizes the impact of
XP Business Copy operations on I/O performance, while a faster copy pace produces copies
more quickly but may affect I/O performance.
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Load sharing of parity groups:
XP Business Copy P-VOLs or S-VOLs should not be concentrated in the same parity group. To
disperse workloads of the parity groups, P-VOLs and S-VOLs should be evenly distributed
across parity groups. XP Business Copy pairs for which XP Business Copy operations are
performed simultaneously should be in different parity groups. If XP Business Copy pairs are
concentrated in only a few parity groups, the host I/O performance may be degraded. To
minimize the effect on the host I/O performance, take the following actions:
◦ Specify Slower for the copy pace when you create, split, or resynchronize the XP Business
Copy pairs.
◦ To perform copy operations on XP Business Copy pairs that are in the same parity group,
reduce the number of pairs at one copy operation. For example, to split multiple XP
Business Copy pairs in the same parity group, wait until one pair is completely split before
splitting another pair.
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Structure for the case using multiple program products simultaneously:
If you are using more than one storage system data management program product (for example,
XP Business Copy, XP Continuous Access, Open Volume Management, Cache Residency
Manager) at the same time in the same storage system, contact HP technical support to ensure
that your storage system is optimized for your configuration of concurrent operations (for
example, sufficient cache).
Each storage system program product can affect the performance of the storage system and/or
the operation of other program products. For example, XP Business Copy and XP Continuous
Access operations both involve initial copy operations and update copy operations to the
secondary/remote volumes in addition to the host I/O workload.
48 Preparing for XP Business Copy Operations