2. The mode must be used with System Option Mode 898.
3. Narrowing the gray zone increases the number of pages
to migrate between tiers per relocation.
4. When Tier1 is SSD while System Option Mode 901 is set
to ON, the effect of System Option Mode 897 and 898 to the
gray zone of Tire1 and Tier2 is disabled and the System
Option Mode 901 setting is enabled instead. In addition, the
settings of System Option Mode 897 and 898 are effective
for Tire2 and Tier3.
Please also see spreadsheet "System Option
Mode_897_898_901" for more details about the relations
between Mode 897, 898 and 901.
898
By the combination of System Option Mode 898 and 897
setting, the expansion width of Tier Range upper I/O value
(IOPH) can be changed as follows.
Mode 898 = ON
:
System Option Mode 897 is OFF: 110%+1IO
System Option Mode 897 is ON: 110%+2IO
Mode 898 = OFF (Default)
:
System Option Mode 897 is OFF: 110%+5IO (Default)
System Option Mode 897 is ON: 110%+0IO
By setting the System Option Modes to ON to lower the
upper limit for each tier, the gray zone between other tiers
becomes narrow and the frequency of page allocation
increases.
Notes
:
1. Apply the mode when the usage of upper tier is low and
that of lower tier is high.
2. The mode must be used with System Option Mode 897.
3. Narrowing the gray zone increases the number of pages
to migrate between tiers per relocation.
4. When Tier1 is SSD while Mode 901 is set to ON, the
effect of system option mode 897 and 898 to the gray zone
of Tire1 and Tier2 is disabled and the Mode 901 setting is
enabled instead. In addition, the settings of Mode 897 and
898 are effective for Tire2 and Tier3.
Please also see spreadsheet "System Option
Mode_897_898_901" for more details about the relations
between System Option Mode 897, 898 and 901.
OFF
899
In combination with the system option mode 900 setting,
whether to execute and when to start the I/O synchronous
copy change as follows.
Mode 899 = ON:
System option mode 900 is ON: I/O synchronous copy
starts without retrying Volume Migration.
OFF
72
System option modes
Hitachi Virtual Storage Platform G400, G600 Hardware Reference Guide
Summary of Contents for Virtual Storage Platform G400
Page 1: ...Hitachi Virtual Storage Platform G600 Hardware Reference Guide MK 94HM8022 05 June 2016 G400 ...
Page 6: ...6 Hitachi Virtual Storage Platform G400 G600 Hardware Reference Guide ...
Page 16: ...16 Preface Hitachi Virtual Storage Platform G400 G600 Hardware Reference Guide ...
Page 123: ...Hitachi Virtual Storage Platform G400 G600 Hardware Reference Guide ...