Fujitsu DX440 S2 Computer Drive User Manual


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Chapter 11 System Management
11.2 Functions in the Action Area for System
ETERNUS Web GUI User’s Guide
Copyright 2013 FUJITSU LIMITED P2X0-1090-10ENZ0
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[Example]
Three TPVs (TPV#0, TPV#1, and TPV#2) are registered in a single TPP.
A single TPP is configured with four RAID groups (RAID group #0, RAID group #1, RAID group #2, and
RAID group #3).
- TPP balancing
Physical area is allocated in the following order regardless of the TPV in which the data is
written.
RAID group#0 RAID group#1 RAID group#2 RAID group#3 RAID group#0 → ...
- TPV balancing
When data is written in TPVs that are registered in the TPP, the physical area is allocated in the
following order.
TPV#0:
RAID group#0 RAID group#1 RAID group#2 RAID group#3 RAID group#0 → ...
TPV#1:
RAID group#1 RAID group#2 RAID group#3 RAID group#0 RAID group#1 → ...
TPV#2:
RAID group#2 RAID group#3 RAID group#0 RAID group#1 RAID group#2 → ...
Cache Mirroring
Select whether to enable or disable the cache mirroring.
To change the setting, select the "Change" checkbox, and then select "Enable" or Disable". If the
"Change" checkbox is cleared after the setting is changed, the value returns to the previous state
when this function is first started.
The cache mirroring function duplicates user data in the cache memory with 2CMs to prevent user
data from being lost when the ETERNUS DX Disk storage system fails or while maintenance
operations are being performed.
- Enable
This mode protects user data from being lost when the ETERNUS DX Disk storage system fails or
while maintenance operations are being performed.
By duplicating the user data in the cache memory, the user data is protected even when one of
the CM fails.
- Disable
This mode is used only when a user can recover the data (for example, when High Performance
Computing is used).
This mode gives priority to improving sequential write performance over reliability. In this case,
user data is lost when the ETERNUS DX Disk storage system fails or maintenance is performed.
The "Thin Provisioning Allocation Mode" is available only when the Thin Provisioning license has
been registered.
It is not necessary to change the default setting ("Enable") for normal use.
Rebooting the ETERNUS DX Disk storage system is required to enable the new configuration.
The current cache mirroring setting and the cache mirroring setting after rebooting can be
checked. Refer to "11.1.12 System Settings" (page 731)
for details.