Apple Xserve RAID: Using RAID 1.2 Admin and Disk Utility - Manual (Page 32)

32 Chapter 3 Monitoring Status and Changing Settings
To set up drive cache and controller cache:
1 Open RAID Admin and click Settings.
2 If necessary, enter the management password and click OK.
3 Click the Performance button.
4 To set up drive cache, click checkbox for the array for which you want to enable or
disable the drive cache.
5 To set up controller cache, click the button you want for Write Cache and Read Prefetch
for each controller.
• Write Cache is used to complete data transactions from the host computer before
actually writing the data to the drives.
• Read Prefetch anticipates that data should be retrieved from the arrays in sequential
order and “reads ahead.” In general, a large Read Prefetch setting is recommended
for video playback, and a small Read Prefetch setting is recommended for database
applications. Tuning the Read Prefetch setting may be required for optimal
performance, depending on your actual data.
6 Click OK.
7 In the confirmation window that appears, click OK.
Note: Drive cache and controller write cache are required for applications that have a
very high throughput, such as high-resolution video editing. UPS backup for drive
cache is highly recommended.