Performance Tuning
Striping Size Expansion
Striping Size Expansion is a function to expand the stripe depth value by specifying the stripe depth
when creating a RAID group.
Expansion of the stripe size enables advanced performance tuning. For normal operations, the de-
fault value does not need to be changed.
An expanded stripe depth reduces the number of drives that are accessed. A reduced number of
commands to drives improves the access performance of the corresponding RAID1+0 RAID groups.
However, it should be noted that an expanded stripe depth may reduce the sequential write per-
formance for RAID5.
The stripe depth values that are available for each RAID level are shown below.
Table 36 Available Stripe Depth
RAID level Drive configuration (*1) Available stripe depth
Mirroring (RAID1) 1D+1M —
High performance (RAID1+0) All drive configurations 64KB, 128KB, 256KB, 512KB, and 1,024KB
Striping (RAID0)
High capacity (RAID5) 2D+1P – 4D+1P 64KB, 128KB, 256KB, and 512KB
5D+1P – 8D+1P 64KB, 128KB, and 256KB
9D+1P – 15D+1P 64KB and 128KB
Reliability (RAID5+0) All drive configurations 64KB
High reliability (RAID6)
High reliability (RAID6-FR)
*1: D: Data, M: Mirror, P: Parity
•
The read/write performance of the random access can be enhanced by changing the setting,
however, note that the performance can be degraded, depending on the used system.
•
The following restrictions are applied to the RAID groups with expanded stripe sizes:
-
Encryption and Logical Device Expansion cannot be performed on the volumes which belong
to the RAID group.
-
RAID groups with different stripe sizes configured cannot coexist in the same TPP or FTSP
pools.
-
A WSV cannot be configured by concatenating RAID groups with different stripe sizes.
•
"Stripe Depth 512KB" cannot be specified for a "RAID5 (4D+1P)" configuration that is used for
TPPs and FTSPs.
•
"Stripe Depth 256KB" cannot be specified for a "RAID5 (8D+1P)" configuration that is used for
TPPs and FTSPs.
2. Basic Functions
Performance Tuning
103
Fujitsu Storage ETERNUS DX100 S4/DX200 S4, ETERNUS DX100 S3/DX200 S3 Hybrid Storage Systems
Design Guide (Basic)
Copyright 2023 Fujitsu Limited
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