Flexible Tier
Flexible Tier provides the following functions:
•
Automated Storage Tiering
This function automatically reallocates data according to the data access frequency and optimizes
performance and cost.
•
FTRP Balancing
I/O access to a virtual volume can be distributed among the RAID groups in a pool by relocating and balancing
the physical areas allocated to the virtual volume.
•
TPV/FTV Capacity Optimization
Data in physically allocated areas are checked in blocks and unnecessary areas (areas where 0 is allocated to
all of the data in each block) are released to unallocated areas.
For details on these functions, refer to
"TPV/FTV Capacity Optimization" (page 55)
.
•
Automated QoS
The QoS for each volume can be controlled by using the ETERNUS SF Storage Cruiser's QoS management
option.
For details on Automated QoS, refer to the ETERNUS SF Storage Cruiser manual.
Automated Storage Tiering
The ETERNUS AF uses the Automated Storage Tiering function of ETERNUS SF Storage Cruiser to automatically
change data allocation during operations according to any change in status that occurs. ETERNUS SF Storage
Cruiser monitors data and determines the redistribution of data. The ETERNUS AF uses the Flexible Tier function
to move data in the ETERNUS AF according to requests from ETERNUS SF Storage Cruiser.
The Flexible Tier function automatically redistributes data in the ETERNUS AF in the hierarchical storage
according to the access frequency by setting the access priority of each RAID level. Data can be moved in blocks
(252MB) that are smaller than the volume capacity.
The data transfer unit differs depending on the chunk size. The following table shows the relationship between
the data transfer unit and the chunk size.
Table 25
Chunk Size and Data Transfer Unit
Chunk size
Transfer unit
21MB
252MB
42MB
504MB
84MB
1,008MB
168MB
2,016MB
336MB
4,032MB
The Automated Storage Tiering function allows the optimization of the RAID levels according to the performance
and the storage efficiency.
Furthermore, because data is reallocated automatically, it can reduce the workload on the administrator for
designing storage performance.
Flexible Tier uses pools configured with multiple RAID groups (Flexible Tier Sub Pools: FTSP) and larger pools
(Flexible Tier Pools: FTRP) comprised of FTSP layers. Volumes used by Flexible Tier are referred to as Flexible Tier
Volumes (FTV).
Settings and operation management for the Flexible Tier function are performed with ETERNUS SF Storage
Cruiser. For more details, refer to "ETERNUS SF Storage Cruiser Operation Guide for Optimization Option".
2. Basic Functions
Operations Optimization (Deduplication/Compression and Storage Virtualization)
56
Design Guide
Summary of Contents for ETERNUS AF S3 Series
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