How to send SCSI instructions to USB devices on MacOS system? The relevant operation can be seen from the official website: first, the primary port is obtained, then the dictionary is traversed to find the relevant device, then the exclusive permission of the device is obtained through the underlying interface, and finally SCSI instruction is sent and data is returned. When you get exclusive access through ObtainExclusiveAccess, the system always returns kIOReturnBusy, causing the device to be busy. May I ask why the USB device just inserted fails to obtain its exclusive permission, indicating that the device is busy? Is there any way to get exclusive rights from the MacOS system? Hope to get your help or advice, thank you!