Advanced Data Guarding User Guide

3-8 Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide
Compaq Confidential – Need to Know Required
Writer: John Turner Project: Advanced Data Guarding for the Smart Array 5300 Controller Reference Guide Comments: final draft
Part Number: 188270-xx1 File Name: d-ch3 System Setup.doc Last Saved On: 12/11/00 12:02 PM
4. Click the Settings button in the Controller section on the right side of the
Main ACU screen.
5. In the Accelerator Ratio section of the Controller Settings screen that is
displayed, either click a check box by one of the choices offered or enter
a percentage in one of the fields.
6. Click the Done button.
7. Choose Save Configuration from the Controller menu.
8. Choose Exit from the Controller menu.
You may also need to change the stripe size. This is described in the following
section.
Optimizing the Stripe Size
Stripe size is the size of the data block written to a hard drive in each stripe of
the logical drive. Table 3-1 summarizes the stripe sizes available for each of
the fault tolerance methods. The default stripe size gives acceptable
performance in most circumstances. When high performance is important, you
can modify the stripe size according to the information in Table 3-2.
Table 3-1
Available Stripe Sizes
Fault Tolerance Method Available Stripe Sizes (kB) Default Size (kB)
RAID 0 128, 256 128
RAID 1 or 0+1 8, 16, 32, 64, 128, 256 128
RAID 5 or RAID ADG 8, 16, 32, 64 16
Table 3-2
Optimum Stripe Size
Type of Server Application Suggested Stripe Size Change
Mixed read/write Accept the default value
Mainly read (such as database or
Internet applications)
Larger stripe sizes work best
Mainly write (such as image
manipulation applications)
Smaller stripes for RAID 5, RAID ADG
Larger stripes for RAID 0, RAID 0+1, RAID 1