Current Write Policy

This item indicates the status of the current write cache for this logical drive. The status varies depending on the setting of write cache for each logical drive, setting of write cache for the entire controller (Adaptive Writeback Cache), existence of battery connection and battery status in the battery connection environment. For Adaptive Writeback Cache, see “3.5.2 Controller.”

Setting of Adaptive

Battery status

Write Policy (setting of

Current Write Policy

Writeback Cache

 

write cache for each

 

 

 

logical drive)

 

Disable

No battery connected or

Write Back

Write Back

 

abnormal status

 

 

 

Write Through

Write Through

 

 

 

Battery connected and

Write Back

Write Back

 

normal status

 

 

 

Write Through

Write Through

 

 

 

 

 

 

Enable

No battery connected or

Write Back

Write Through

 

abnormal status

 

 

 

Write Through

Write Through

 

 

 

Battery connected and

Write Back

Write Back

 

normal status

 

 

 

Write Through

Write Through

 

 

Settings tab

Alias

Alias name

 

 

Read Policy

Read Cache: Uses cache in reading.

 

Read Ahead: Uses cache in reading and provides read ahead. Improves

 

performance by read ahead before request.

 

No Cache: Does not use cache in reading.

Write Policy

Write Through: Does not use cache in writing.

 

Write Back: Always uses cache in writing. It is expected that the setting can

 

improve write performance.

 

However, despite the setting, the actual write cache status may vary depending

 

on the setting of write cache for the controller (Adaptive Writeback Cache) and

 

the battery status. See the description of the Current Write Policy in the

 

Information tab in "3.5.9 Logical Drive" for details.

If you change either or both of the policies, click [Submit] to enable the change.

IMPORTANT: If you change an option for Read Policy, it is validated immediately, regardless of clicking of Submit or Reset button.

Background Activities tab

If you click the center of the Background Activities tab, the BGA being executed in the selected disk array appears. Clicking the arrow at the right end of the tab allows the BGA start menu items executable at the RAID level (including Initialize and Redundancy Check) to be displayed.

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