Changing The Cache Read/Write Ratio; Optimizing The Stripe Size - Compaq 166207-B21 - Smart Array 5302/32 RAID Controller Reference Manual

•
Change to a stripe size that is more suitable for the type of data transfer common
to the system.
•
Change the RAID level to one that requires less RAID overhead.
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Enlarge the logical drive to span all available controller channels.

Changing the Cache Read/Write Ratio

By default, the array accelerator cache capacity is equally divided between reads and
writes. If the typical server application has significantly more reads than writes (or
vice versa), you may improve system performance if you change this setting.
NOTE: RAID operations use 32 MB of the cache.
1. Double-click the ACU icon on the desktop.
2. Select the controller from the drop-down list on the main ACU screen.
3. Select the array in the configuration view window.
4. Click Settings in the Controller box.
5. In the Accelerator Ratio box on the Controller Settings screen, set the ratio of
read cache to write cache.
6. Click Done.
7. Select Save Configuration from the Controller menu.
8. Select Exit from the Controller menu.

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 2-1 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 2-2.
Compaq Advanced Data Guarding Option Software Reference Guide
System Setup
2-9