Hitachi g600 Reference Manual page 55

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 GUI
In case of System Option Mode 457 On, the high speed
LDEV format for external volumes was supported at V03.
Since V04, Control Block Write of the external LDEVs in
Mainframe emulation has been supported by Storage
Navigator (GUI).
- In case the LDEV is not written with data "0" before
performing the function, the LDEV format may fail.
- After the format processing, make sure to set System
Option Mode 457 to OFF.
PAIR → PSUS(SP) → PSUS: System Option Mode 459
459
function is running at copy pending from P-VOL to S-VOL
such as PSUS(SP) → PSUS. Please refer additional TAB of
mode list.
Mode 459 = ON:
Waits for cache memory to completely destage the DKC S-
Vol to the External Volume S-Vol before changing pair status
to SUSPEND.
Mode 459 = OFF:
The status changes to SUSPEND as soon as all the delta
data is copied to S-Vol cache. The status does not wait for
cache to destage to the S-Vol external volume.
Universal Replicator recommends the line band of 100 Mbps
466
or more for the path between Main and Remote. However,
when a customer uses the line band of around 10 Mbps,
operation on UR cannot be properly processed. As a result,
many retries occur and UR may suspend. This mode is
provided to guarantee the line band of at least 10 Mbps for
proper system operation.
Mode 466 = ON:
The line band of 10 Mbps or more is available. The JNL read
is performed with 4-multiplexed read size of 256 KB.
Mode 466 = OFF:
The same as the conventional operation. The line band of
100 Mbps or more is available. The JNL read is performed
with 32-multiplexed read size of 1 MB by default.
Note that the line band can be changed from the window for
changing JNL group options.
In case of using the following features, the current copy
467
processing slows down if the dirty percentage is 60% or
larger, and it stops if the dirty percentage is 75% or larger.
Mode 467 is to prevent the dirty percentage from over 60%
so that the host performance is not affected.
Hitachi Virtual Storage Platform G400, G600 Hardware Reference Guide
System option modes
OFF
OFF
ON
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