HP XP7 for Compatible FlashCopy Mirroring User Guide (TK940-96001)

Optimizing Volumes
Volumes can be optimized by Compatible FlashCopy if you use the DEFRAG command of the
DFSMSdss utility with the FASTREPLICATION option. See the IBM FlashCopy manual for details of
the option.
CAUTION: The DEFRAG command may generate an error because the number of relationships
per volume exceeds the maximum when all the following conditions are met.
• The parity group including the volume is overloaded when accessed too many times.
• The DEFRAG command is executed with FASTREPLICATION(REQUIRED).
To avoid an error, avoid using the FASTREPLICATION option or specify
FASTREPLICATION(PREFERRED). If you specify FASTREPLICATION(REQUIRED), you must reduce
workloads on the parity group.
Optimizing Volumes 35