IBM SG24-4763-00 manual Setting the Write Policy

Models: SG24-4763-00

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Note

It is not necessary to define multiple logical drives of the same RAID level. You can partition these logical drives the same way you partition a real disk when you install the operating system.

8.Select Exit to leave this menu.

9.Select Yes to save the changes.

Figure 40 shows an example of a completed array definition that includes two logical drives: one 400MB RAID-5 array and one 2925MB RAID-1 array.

 

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IBM RAID Controller Configuration Ver 2.12

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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40. RAID Configuration Program - Result

 

 

 

 

 

 

 

 

 

2.5.1.6 Setting the Write Policy

Now that the logical drives have been created, you may wish to change the write policy for these drives.

If you want to change the write policy:

1.Select Advanced functions from the main menu.

2.Select Change write policy.

3.Use the up and down arrow keys to select the logical drive.

4.Press Enter to toggle the write policy.

The different options are as follows:

WB for Write-Back

In the write-back mode, the completion status is sent before the data is actually written to the drives. While this mode will yield higher performance, it is critical to protect the DASD power to ensure the write operations actually complete, since the processor thinks the operation has been completed.

WT for Write-Through

Chapter 2. H a r d w a r e Configuration 47

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IBM SG24-4763-00 manual Setting the Write Policy