PS4210 Hardware Owner's Manual 1 Basic Storage Array InformationBack-Panel Features and IndicatorsThe back of a PS4210 is shown in Figure 5.Table 2 describes the back-panel features.Figure 5: Back-Panel FeaturesTable 2: Array Back-Panel FeaturesItem Feature Identifier Description1 Power switch None The power switch controls the power supply output to the array. Oneswitch on each power supply.2 Power supply unit(PSU)PSU0 (left)PSU1 (right) Power supply and cooling fan module for array.3 Control module CM0 (top)CM1 (bottom)The control module provides:• Connection to a data path between the array and the applicationsusing the storage• Array management functions for your array4 Control modulerelease lever None Enables you to remove the control module from the array.Shutting Down and Restarting an ArrayA PS Series array includes redundant, hot-swappable drives, power supplies, and control modules (in a dualcontrol module array). You can remove a redundant component without affecting operation if a functioningcomponent is available. Otherwise, Dell recommends that you cleanly shut down the array and turn off powerbefore removing a component.When an array is shut down, any volumes with data on the array will be set offline until the array is successfullyrestarted. Being offline affects initiators that are connected to the volumes.Array shutdown procedure1. Connect to the array in one of the following ways:4