2.
Basic Functions
Optimization of Volume Configurations
One volume for the Extreme Cache Pool is created for each controller. Different capacities can
be set for each controller.
To expand the Extreme Cache Pool capacity, disable "Extreme Cache Pool". After that, enable
"Extreme Cache Pool (Expanded)", increase the number of member drives, and redefine the SSDs
used for the Extreme Cache Pool.
For the ETERNUS DX100 S3/DX200 S3
•
The capacity that can be used as an Extreme Cache Pool is 400GB for each controller. Specify a
single SSD to be used for each controller.
SSDs with a capacity of 400GB, 800GB, and 1.6TB can be used for Extreme Cache Pools. If an SSD
larger than 400GB is selected, the remaining area cannot be used.
Volumes for the Extreme Cache Pool are created in the specified SSD. One volume for the Ex-
treme Cache Pool is created for each controller.
The Extreme Cache Pool function can be enabled or disabled for each volume. Note that the Ex-
treme Cache Pool function cannot be enabled for Deduplication/Compression Volumes, or vol-
umes that are configured with SSDs.
SSDs that are already in use cannot be specified for Extreme Cache Pools.
•
The Extreme Cache function may improve random I/O.
•
Optimization of Volume Configurations
The ETERNUS DX allows for the expansion of volumes and RAID group capacities, migration among
RAID groups, and changing of RAID levels according to changes in the operation load and perform-
ance requirements. There are several expansion functions.
Table 22 Optimization of Volume Configurations
Function/usage
RAID Migration
Logical Device
Expansion
LUN Concatena-
tion
Wide Striping
¡: Possible, ´: Not possible
*1: For TPVs or FTVs, the capacity cannot be expanded during a migration.
●
Expansion of Volume Capacity
•
RAID Migration (with increased migration destination capacity)
When volume capacity is insufficient, a volume can be moved to a RAID group that has enough
free space. This function is recommended for use when the desired free space is available in the
destination.
Fujitsu Storage ETERNUS DX100 S4/DX200 S4, ETERNUS DX100 S3/DX200 S3 Hybrid Storage Systems Design Guide (Basic)
Volume expan-
RAID group ex-
sion
pansion
´
¡ (Adding ca-
pacity during mi-
gration) (*1)
´
¡
´
¡ (Concatenat-
ing free spaces)
´
´
Copyright 2023 Fujitsu Limited
Migration among
RAID groups
¡
´
´
´
55
Changing the
Striping for RAID
RAID level
groups
´
¡
´
¡ (Adding drives
to existing RAID
groups)
´
´
´
¡
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