System Administration Guide: Devices and File Systems

Hot-Plugging USB Devices With the cfgadm Command

You can add and remove a USB device from a running system without using the cfgadm command. However, a USB device can also be logically hot-plugged without physically removing the device. This scenario is convenient when you are working remotely and you need to disable or reset a non functioning USB device. The cfgadm command also provides a way to display the USB device tree, including manufacturer and product information.

The cfgadm command displays information about attachment points, which are locations in the system where dynamic reconfiguration operations can occur. An attachment point consists of the following:

Attachment points are represented by logical and physical attachment point IDs (Ap_Ids). The physical Ap_Id is the physical path name of the attachment point. The logical Ap_Id is a user-friendly alternative for the physical Ap_Id. For more information on Ap_Ids, see cfgadm_usb(1M).

The cfgadm command provides the following USB device status information.

Receptacle State 



The device is not physically connected. 


The device is logically disconnected and unavailable, even though the device could still be physically connected. 


The device is logically connected, but unavailable. The device is visible in prtconf output.


The device is connected and available. 

The following sections describe how to hot-plug a USB device through the software with the cfgadm command. All of the sample USB device information in these sections has been truncated to focus on relevant information.