HP Hitachi ShadowImage for Mainframe User Guide (T5213-96032, November 2011)

heavy, it is more likely that host server I/O performance (response) may be degraded. The Copy
Threshold option temporarily stops SIz copy operations when the load of the storage system is
heavy. If you set this option in effect, you can minimize the degradation of host I/O performance
by temporarily stopping SIz copy operations when the load of the storage system is heavy.
ShadowImage for Mainframe has another option called the Host I/O Performance option, which
maintains host I/O performance (response). Host I/O Performance option suppresses SIz copy
operation regardless of the status of the storage system. On the other hand, the Copy Threshold
option is effective only when the load of the storage system is heavy. When the Copy Threshold
option is in effect, all the SIz copy operations stop.
For information about the setting of the Host I/O Performance option, see (page 25). For information
about the setting of the Copy Threshold option call the HP technical support.
Copy operations that are stopped by the Copy Threshold option will resume when the storage
system load becomes light. If this option is in effect, the SIz copy operation and the copy operations
of the following program products will stop when the storage system load is heavy:
• HP XP Business Copy Software
• HP XP for FlashCopy Mirroring Software
• HP XP for FlashCopy Mirroring V2 Software
• HP XP Snapshot Software
• HP XP Auto LUN Software
26 About ShadowImage for Mainframe Operations