Hitachi Virtual Storage Platform, Руководство пользователя и справочник

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Functional and Operational Characteristics
2–45
Hitachi VSP User and Reference Guide
894 Mainframe By disabling context switch during data transfer,
response time in low I/O load is improved.
Mode 894 = ON:
When all the following conditions are met, the
context switch is disabled during data transfer.
1. The average MP operating rate of MP PCB is less
than 40 %, or the MP operating rate is less than
50%.
2. Write pending rate is less than 35 %.
3. Data transfer length is within 8 KB.
4. The time from job initiation is within 1600 ?s
Mode 894 = OFF (default):
The context switch is enabled during data transfer.
Notes:
1. This mode is applied when improvement of I/O
response performance in low workload is
required.
2. Because the processing on the Mainframe
target port is prioritized, other processing may
take longer time compared to that when the
mode is set to OFF.
OFF
895 TrueCopy for
Mainframe Setting the mode to ON or OFF, the link type with
transfer speed of 8 GBps or 4 GBps is reported
respectively.
Mode 895 = ON:
When the FICON/FC link up speed is 8 GBps, the
link type with transfer speed of 8 GBps is reported.
Mode 895 = OFF (default):
The link type with transfer speed of up to 4 GBps is
reported , even when the actual transfer speed is 8
GBps.
Notes:
1. To apply the mode, set the RMF version of
mainframe to be connected to 1.12 or higher.
2. If the OS does not use a supported version, the
transfer speed cannot be displayed correctly.
OFF ..
Mode Category Description Default MCU/RCU