The Oracle Solaris OS uses the World Wide Name (WWN) syntax in place of the locally unique tn (target ID) field in logical device names. This change affects how device names can be mapped to specific SCSI devices. The following points are key to understanding the impact of this change:
Before the change to WWN nomenclature, the Oracle Solaris OS would ordinarily identify the default boot device as c0t0d0.
With the change, the device identifier for the default boot device is now referred to as c0tWWNd0, where WWN is a hexadecimal value that is unique to this device throughout the world.
This WWN value is assigned by the manufacturer of the device and, therefore, has a random relationship to the server’s device tree structure.
Because WWN values do not conform to the traditional logical device name structure, you cannot directly identify a target device from its c#tWWNd# value. Instead, you can use one of the following alternative methods to map WWN-based device names to physical devices.
One method consists of analyzing the output of the OBP command probe-scsi-all. You use this method when the OS is not running. See Mapping WWN Values to Hard Drives (OBP probe-scsi-all Command) for more information.
Note - For example, you would analyze probe-scsi-all output when you want to identify a boot device.
When the OS is running, you can analyze the output of the command prtconf -v. See Identify a Disk Slot Using prtconf (Oracle Solaris OS) for more information.