Monitoring and Maintenance Activities
Manual No. 775029
4-43
How Do I Change Physical Drive Read and Write
Cache Settings?
If you are unfamiliar with the terms “Read Cache,” “Read Ahead,” “Write
Cache,” “Write Through,” or “Write Back” caching, please refer to the
Glossary for a detailed definition.
In a nutshell, Read Ahead caching speeds read performance in situations
where large blocks of sequential data need to be read. For random read
situations, however, it may actually reduce performance.
Write Back caching speeds write performance but risks loss of data in the
cache buffer should power fail. Use Write Back only if you have a battery
backup unit (BBU) or uninterruptable power supply (UPS) installed to
preserve data in the cache.
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Open the Device Configuration screen as described in “How
Do I View Physical Drive Status and Information?” on page 4-39.
☞
Use the arrow key to select the Read Cache field, then...
☞
Press the + or - key to find your desired caching method
(“Enabled” = Read-Ahead, or “Disabled” = Normal),
OR
☞
Press Spacebar to display a box of available choices, use the
arrow key to select your desired read caching choice, then press
Enter.
☞
Use the arrow key to select the Write Cache field, then...
☞
Press the + or - key to find your desired caching method
(“Enabled” = Write-Back, or “Disabled” = Write-Thru),
OR
☞
Press Spacebar to display a box of available choices, use the
arrow key to select your desired write caching choice, then
press Enter.
Once you’ve set the Read Cache and Write Cache as desired,
