Performance Tuning; Striping Size Expansion; Table 26 Available Stripe Depth - Fujitsu ETERNUS DX60 S4 Design Manual

1. Function

Performance Tuning

Performance Tuning

Striping Size Expansion

Striping Size Expansion is a function to expand the stripe depth value by specifying the stripe depth when creat-
ing a RAID group.
Expansion of the stripe size enables advanced performance tuning. For normal operations, the default 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 performance for RAID5.
The stripe depth values that are available for each RAID type are shown below.

Table 26 Available Stripe Depth

RAID type
Mirroring (RAID1)
High performance (RAID1+0)
Striping (RAID0)
High capacity (RAID5)
Reliability (RAID5+0)
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:
•
Logical Device Expansion cannot be performed on volumes that belong to the RAID group.
-
- RAID groups configured with different stripe sizes cannot coexist in the same TPP pool.
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.
•
"Stripe Depth 256KB" cannot be specified for a "RAID5 (8D+1P)" configuration that is used for TPPs.
•
FUJITSU Storage ETERNUS DX60 S4, ETERNUS DX60 S3 Hybrid Storage Systems Design Guide (Basic)
Drive configuration (*1)
1D+1M
All drive configurations
2D+1P – 4D+1P
5D+1P – 8D+1P
9D+1P – 15D+1P
All drive configurations
80
Copyright 2019 FUJITSU LIMITED
Available stripe depth
—
64KB, 128KB, 256KB, 512KB, and 1,024KB
64KB, 128KB, 256KB, and 512KB
64KB, 128KB, and 256KB
64KB and 128KB
64KB
P3AM-8992-14ENZ0