Use the FC Slower Copy1 option to give priority to host I/O response over background copy processing of Compatible FlashCopy® relationships.
When this option is enabled, the maximum number of Compatible FlashCopy® relationships that can be copied simultaneously in the background is reduced by 50%, thus improving host I/O response. When the FC Slower Copy2 option is enabled, the FC Slower Copy1 option is invalid.
When Compatible FlashCopy® background copy operations are suppressed by the FC Slower Copy1 option, the time required for background copying increases. Background copy operation time vary depending on the relationships, so the FC Slower Copy1 option will not necessarily double the time compared to when the option is not specified.
If ShadowImage pairs exist in the same parity group as Compatible FlashCopy® volumes, the host I/O response time might not improve.