HP XP7 Owner's Manual page 44

Table 1 1 System option modes (continued)
Mode Category
855 Business
Copy/Snapshot,
ShadowImage for
Mainframe, Auto
LUN V2
857 OPEN and
Mainframe
867 Dynamic
Provisioning
44 Functional and operational characteristics
Description
1. 1. This mode is applied when
- a file system using THP pool VOLs is used.
- Data Retention Utility is installed.
2. 2. Because the DRU attribute is set to Protect for the V-VOL, a
read I/O is also disabled.
3. 3. If Data Retention Utility is not installed, the expected effect
cannot be achieved.
4. 4. The Protect attribute of DRU for the HDP V-VOL can be
released on the Data Retention window of Storage Navigator
after recovering the blocked pool VOL.
By switching the mode to ON/OFF when Business
Copy/Snapshot 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%.
Notes:
1. This mode 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 mode 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 mode is set
to ON
This mode enables or disables to limit the cache allocation
capacity per MPB to within 128 GB except for cache residency.
Mode 857 = ON:
The cache allocation capacity is limited to within 128 GB.
Mode 857 = OFF (default):
The cache allocation capacity is not limited to within 128 GB.
Note:
This mode is used with HP XP7 microcode version -04
(70-04-0x-00/00) and earlier. It is also applied when
downgrading the microprogram from V02 (70-02-02-00/00) or
higher to a version earlier than V02 (70-02-02-00/00) while
over 128 GB is allocated.
All-page reclamation (discarding all mapping information between
THP pool and THP volumes) is executed in DP-VOL LDEV format.
This new method is enabled or disabled by setting the mode to
ON or OFF.
Mode 867 = ON:
Default MCU/RCU
OFF -
OFF ..