Mode
Category
Description
Default
MCU/RCU
This mode is applied when performance improvement at
sequential write in UVM configuration is required.
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
896
Dynamic
Provisioning
Dynamic
Provisioning for
Mainframe,
Dynamic Tiering
Dynamic Tiering
for Mainframe,
Hitachi Thin
Image
The mode enables or disables the background format
function performed on an unformatted area of a HDP/HDT
pool.
For information regarding operating conditions, refer to
Provisioning Guide for Open Systems or Provisioning Guide
for Mainframe Systems.
Mode 896 = ON (default)
The background format function is enabled.
Mode 896 = OFF
The background format function is disabled.
Notes:
1.
The mode is applied when a customer requires the
background format for a HDP/HDT pool in the
environment where new page allocation (for
example, when system files are created from a host
for newly created multiple HDP VOLs), frequently
occurs and the write performance degrades because
of an increase in write pending rate.
2.
When the mode is set to ON, because up to 42MB/s
of ECCG performance is used, local copy performance
may degrade by about 10%. Therefore, confirm
whether the 10% performance degradation is
acceptable or not before setting the mode to ON.
3.
When a Dynamic Provisioning VOL that is used as an
external VOL is used as a pool VOL, if the external
pool becomes full due to the background format, the
external VOL may be blocked.
If the external pool capacity is smaller than the
external VOL (Dynamic Provisioning VOL), do not set
the mode to ON.
ON
897
Dynamic Tiering,
Dynamic Tiering
for Mainframe
By the combination of SOM 897 and 898 setting, the
expansion width of Tier Range upper I/O value (IOPH) can
be changed as follows.
OFF
System option modes
163
Hitachi Virtual Storage Platform G1000, G1500, and Virtual Storage Platform F1500 Hardware Guide