Fujitsu Eternus DX200F, User Manual

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Appendix A Parameter List
A.5 RAID Group Management
ETERNUS Web GUI User’s Guide (Settings)
Copyright 2015 FUJITSU LIMITED P2X0-1270-13ENZ0
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A.5.5 Modify RAID Group Parameters
For details about this function, refer to "5.6 Modify RAID Group Parameters" (page 545) .
For the factory default settings for this function, refer to "Appendix B Modify RAID Group Parameters" (page
1005) .
●
Parameters Setting
• Rebuild Priority
●
Advanced Settings
• DCMF
Description Specify the rebuild priority.
It is not necessary to change the default setting for normal use. When not changing the
setting, select "Do not change".
When host access is not performed, rebuild, copyback, and redundant copy to RAID
groups that is not registered as REC disk buffers are performed with "High" priority
regardless of the "Rebuild Priority" setting.
The rebuild priority of a RAID group cannot be changed if it is registered as an EXCP.
Rebuild, copyback, and redundant copy performance may be improved by specifying a
larger "Rebuild Priority" value. Note that specifying larger "Rebuild Priority" may cause
the degradation of RAID group performance (throughput) when rebuild, copyback, or
redundant copy is being performed in the target RAID group.
Input condition/
Display contents
•
Do not change
•
Low
Perform rebuild, copyback, and redundant copy with a normal priority.
•
Middle
Give the same priority as the host access to rebuild, copyback, and redundant copy.
•
High
Give priority to rebuild, copyback, and redundant copy over host access.
Description Select "Change" and specify the Disk Command Multiplying Factor (DCMF).
It is not necessary to change the default value for normal use. The maximum number of
commands issued to a drive is changed to a multiple represented by the specified value.
(If "DCMF" is "2", the number of commands is doubled. If "DCMF" is "3", the number of
commands is tripled.) When not changing the setting, select "Do not change".
The higher the DCMF value is, the more drive throughput is available, improving
sequential performance. Note that high DCMF value may result in a high load on the
drive, decreasing performance.
Input condition/
Display contents
•
Do not change
•
Change
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