Hitachi Virtual Storage Platform F400, Руководство системного администратора

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Mode Category Description Default MCU/RCU
855 ShadowImage
Volume
Migration
By switching this SOM to ON/OFF when
ShadowImage is used with SOM 467 set to ON, copy
processing is continued or stopped as follows.
Mode 855 = ON: When the amount of dirty data is
within the range from 58% to 63%, the next copy
processing is continued after the dirty data created
in the previous copy is cleared to prevent the amount
of dirty data from increasing (copy after destaging). If
the amount of dirty data exceeds 63%, the copy
processing is stopped.
Mode 855 = OFF (default): The copy processing is
stopped when the amount of dirty data is over 60%.
For details, contact customer support (see SOM855
sheet).
Notes:
1. This SOM is applied when all the following
conditions are met
■
ShadowImage is used with SOM 467 set to
ON.
■
Write pending rate of an MP blade that has
LDEV ownership of the copy target is high
■
Usage rate of a parity group to which the
copy target LDEV belongs is low.
■
ShadowImage copy progress is delayed.
2. This SOM is available only when SOM 467 is set
to ON.
3. If the workload of the copy target parity group is
high, the copy processing may not be improved
even if this SOM is set to ON.
OFF -
System option modes
Appendix B: System option modes
System Administrator Guide for VSP Gx00 models and VSP Fx00 models 319