Chapter 3 Functional Descriptions 23Cache ParametersOptimization for Sequential or Random I/OWhen using RAID with applications such as video or image orientedapplications, the application reads/writes from the drive using large-block, sequential files instead of small-block, random access files.The AA-3102RS RAID controller provides the options to optimize forlarge-sequential I/O or optimize for small-random I/O access."Optimization for Sequential I/O" provides larger stripe size (block size,also known as Chunk size) than "Optimization for Random I/O". A lotof the controller’s internal parameters will also be changed to optimizefor sequential or random I/O. The change will take effect after thecontroller reboots.If the existing logical drives were built with "Optimization for RandomI/O", these logical drives will not read/write when using "Optimizationfor Sequential I/O" (shows "INVALID") and vice versa because thestripe size is different. Change it back to the original setting and resetthe controller to make available the logical drive data again.Changing the setting to "Optimization for SequentialI/O" or "Optimization for Random I/O" should beperformed only when no logical drive exist.Otherwise, you will not be able to access the data inthe logical drive later on.
