Hitachi Universal Storage Platform V, Справочное руководство

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Functional and Operational Characteristics 3-17
Hitachi Universal Storage Platform V/VM User and Reference Guide
Mode Category Function Default MCU/RCU
491 ShadowImage
ShadowImage for
z/OS
FlashCopy V1
Improve the performance of ShadowImage, ShadowImage for
z/OS, and FlashCopy version 1.
Mode 491 = ON: The option (Reserve 05) of SI/SIz is
available. When this option is set to ON, copy operations (SI,
SIz, FCv1) are increased from 64 processes to 128 processes
for improved performance.
Mode 491 = OFF: The option (Reserve 05) of SI/SIz is not
available. The copy operations (SI, SIz, FCv1) are performed
with 64 processes.
Note:
ƒ
Mode 491 requires at least three BED features. If there are
less than three BED features, mode 491 is not effective.
ƒ
Enable mode 491 when the performance of ShadowImage,
ShadowImage for z/OS, and/or is considered to be
important.
ƒ
Do not enable mode 491 when host I/O performance is
considered to be important.
ƒ
When mode 491 is ON, set mode 467 to OFF. If mode 467
is ON, the performance may not improve.
OFF –
493 Mainframe The CUIR function requires that the SA_ID reported to the
host is unique. The SA_ID value cannot be changed during
online operations. To change the SA_ID value from normal to
unique, set mode 493 to ON and then perform a power
cycle*. Setting mode 493 to ON without performing a power
cycle does not enable the function.
*Power cycle includes PS-OFF/ON (volatile/non-volatile),
start-up after breaker OFF/ON, or offline micro-program
exchange.
Mode 493 = ON: When mode 493 is ON and a power cycle is
performed, a unique SA_ID value for each port is reported to
the host.
Mode 493 = OFF: When mode 493 is OFF and a power cycle is
performed, and 2107 port is not set, normal SA_ID values are
reported to the host. When 2107 emulation is set, the SA_ID
value of mainframe PCB port remains unique even after
setting mode 493 to OFF and then performing a power cycle.
Caution: Power cycle is required.
OFF –
494 Mainframe Enables CUIR processing when replacing a FICON PCB.
Mode 494 = ON: CUIR processing is available when replacing
a FICON PCB, but only when mode 493 is ON and a power
cycle* is performed to enable the SA_ID unique mode.
*Power cycle includes PS-OFF/ON (volatile/non-volatile),
start-up after breaker OFF/ON, or offline micro-program
exchange.
Mode 494 = OFF: CUIR processing is not available.
Caution: Power cycle is required.
OFF –