9-2Adaptec Storage Manager Pro User’s GuideBackground tasks are processed only when there is no disk I/O fromthe computer for a period of at least 250 milliseconds. As a result,background tasks take longer to complete, but they have the leastamount of impact to I/O performance.Foreground tasks consume more of the available bandwidth. As aresult, foreground tasks are completed more quickly thanbackground tasks, but they can reduce I/O performance.Note: Regardless of the priority level set for controller tasks,100 percent of the bandwidth is allocated to backgroundtasks when there is no disk drive I/O from the hostcomputer.To set the controller task priority:1 In the System Browser window, select the controller for whichyou want to set the task priority.2 Click Task Priority.The Set Controller Task Priority dialog box appears.3 Move the slider bar between Background and Foregrounddepending on the priority level you want to set:– Background—Completes the tasks in the background anddoes not compete for I/O bandwidth from the hostcomputer. As more tasks are set to the background, it takeslonger to complete tasks, but the background tasks allowfor normal system operation.– Foreground—Speeds up the completion of the tasks;however, as more tasks are set to the foreground, moreavailable bandwidth is consumed by these tasks, thusreducing I/O performance.4 Click OK.Rescanning a ControllerYou can rescan the channels of the selected controller to verify thepresence of existing devices or to recognize new devices added to achannel.
