Hot spare function enables automatic switch over to a spare drive during hard drive failure to ensure business continuity and uninterrupted operations hot swap change drives in raid without down time iscsi target support works simultaneously as nas and iscsi target four usb ports configured with four usb ports two usb 30 ports and two usb 20 ports for greater flexibility use the usb port to add external hard drive printer or ups uninterruptible power supply connectivity new web ma