HP XP7 Owner Guide (H6F56-96006)

Table 11 System option modes (continued)
MCU/RCUDefaultDescriptionCategoryMode
MCU/RCUOFFExternal Storage457 1. High Speed LDEV Format for External Volumes
Mode 457 = ON: The high speed LDEV format for external
volumes is available by setting system option mode 457 to
ON. When System Option Mode 457 is ON, when selecting
the external volume group and performing the LDEV format,
any Write processing on the external logical units will be
skipped. However, if the emulation type of the external LDEV
is a mainframe system, the Write processing for mainframe
control information only will be performed after the write skip.
2. Support for Mainframe Control Block Write GUIMode 457 =
ON: The high speed LDEV format for external volumes is
supported. Control Block Write of the external LDEVs in
Mainframe emulation is supported by Remote Web Console
(GUI).
Notes:
1. If the LDEV is not written with data “0” before performing the
function, the LDEV format may fail.
2. After the format processing, make sure to set system option
mode 457 to OFF.
-OFFWhen the secondary volume of an BC/BC Z pair is an external
volume, the transaction to change the status from SP-PEND to
SPLIT is as follows:
Business Copy Z,
Business Copy
459
1. Mode 459 = ON when creating an BC/BC Z pair: The copy
data is created in cache memory. When the write processing
on the external storage completes and the data is fixed, the
pair status will change to SPLIT.
2. Mode 459 = OFF when creating an BC/BC Z pair Once the
copy data has been created in cache memory, the pair status
will change to SPLIT. The external storage data is not fixed
(current spec).
MCUOFFSIM Report without Inflow LimitContinuous Access
Synchronous Z
464
For Cnt Ac-S, the SIM report for the volume without inflow limit
is available when mode 464 is set to ON.
SIM: RC=490x-yy (x=CU#, yy=LDEV#)
OFFFor Cnt Ac-J/Cnt Ac-J Z operations it is strongly recommended
that the path between main and remote storage systems have a
Continuous Access
Journal, Continuous
Access Journal Z
466
minimum data transfer speed of 100 Mbps. If the data transfer
speed falls to 10 Mbps or lower, Cnt Ac-J operations cannot be
properly processed. As a result, many retries occur and Cnt Ac-J
pairs may be suspended. Mode 466 is provided to ensure proper
system operation for data transfer speeds of at least 10 Mbps.
Mode 466 = ON: Data transfer speeds of 10 Mbps and higher
are supported. The JNL read is performed with 4-multiplexed read
size of 256 KB.
Mode 466 = OFF: For conventional operations. Data transfer
speeds of 100 Mbps and higher are supported. The JNL read is
performed with 32-multiplexed read size of 1 MB by default.
Note: The data transfer speed can be changed using the Change
JNL Group options.
ONFor the following features, the current copy processing slows
down when the percentage of “dirty” data is 60% or higher, and
Business
Copy/Snapshot,
467
it stops when the percentage is 75% or higher. Mode 467 isBusiness Copy
provided to prevent the percentage from exceeding 60%, so that
the host performance is not affected.
Z,Compatible
FlashCopy,
34 Functional and operational characteristics