(Without consideration of exceeding performance limitation,
allocation is done from highly loaded pages until reaching
the capacity limit.
When the capacity of the tier1 reaches the threshold value,
the minimum value of the tier range is set to the starting
value of the lower IOPH zone, and the maximum value of
the lower tier range is set to the boundary value.
Mode 901 = OFF (default)
:
For tier1 (drive type is SSD), page allocation is performed
based on performance potential limitation.
(With consideration of exceeding performance limitation,
allocation is done from highly loaded pages but at the point
when the performance limitation is reached, pages are not
allocated any more even there is free space)
When the capacity of the tier1 reaches the threshold value,
the minimum value of the tier range is set to the boundary
value, and the maximum value of the lower tier range is set
to a value of boundary value x 110% + 5 [IOPH].
Notes
:
1. This mode is applied when pages with the maximum
capacity need to be allocated to tier1 (drive type is SSD)
with DT or DTz.
2. 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.
3. The following is recommended when applying System
Option Mode 901.
The actual I/O value (total number of I/Os of all tiering
policies) < the performance potential value of Tier 1*1 x 0.6
*1: The performance potential value of Tier 1 displayed on
Monitor information by using Dx-ray.
Please also see spreadsheet "System Option Mode
897_898_901" for more details about the relations between
System Option Mode 897, 898 and 901.
904
By setting the mode to ON or OFF, the number of pages to
be migrated per unit time at tier relocation is changed.
Mode 904 = ON:
The number of pages to be migrated at tier relocation is set
to up to one page per second.
Mode 904 = OFF:
No restriction on the number of pages to be migrated at tier
relocation (existing specification).
Notes:
OFF
74
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 ...