Hitachi G1000 - Pair condition and recovery: path failure between the server and storage system

Mode Category Description Default MCU/RCU
Mode 803 = OFF (default):
While a HDP pool VOL is blocked, if a read or write I/O is
issued to the blocked pool VOL, the DRU attribute is not
set to Protect.
Notes:
1. This mode is applied when
• a file system using HDP pool VOLs is used.
• Data Retention Utility is installed.
2. Because the DRU attribute is set to Protect for the V-
VOL, a read I/O is also disabled.
3. If Data Retention Utility is not installed, the expected
effect cannot be achieved.
4. The Protect attribute of DRU for the HDP V-VOL can
be released on the Data Retention window of
Device Manager - Storage Navigator after recovering
the blocked pool VOL.
855 ShadowImage,
ShadowImage
for Mainframe,
Volume Migration
V2
By switching the mode 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%.
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
857
Open and
Mainframe
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.
OFF -
System option modes 161
Hitachi Virtual Storage Platform G1000, G1500, and Virtual Storage Platform F1500 Hardware Guide