Example using a device path from an Ultra Enterprise 3000:

/sbus@3,0/SUNW,fas@3,0/sd@0,0

The first portion of the device path indicates the I/O board slot location.  In Table 1 we see that sbus@3,0 correlates to the I/O board in slot 1, located on the back of the machine (UE 3000's only use the rear, odd number slots because there are internal disks in the front).

The second portion of the device path indicates the type of onboard controller and the Sys I/O bus it uses.  I/O boards are basically split in half, each half is controlled by a Psycho or Sys I/O chip (A or B).
We see that SUNW,fas@3,0 correlates to the onboard (built-in) fast/wide SCSI controller at Sys I/O B on this board.

The next portion of the device path (sd@0,0) correlates to the SCSI disk (sd) set to target id 0 (in this case an internal disk, since only internal disks should be controlled by the onboard SCSI controller of the I/O board in slot 1).
 

Table 1

Other Examples:

/sbus@6,0/SUNW,socal@d,0/sf@0,0/ssd@2200002136bcd49,0 (ssd27)

This device path correlates to an I/O board in slot 3 of a UE server (sbus@6), the onboard socal controller (socal@d), the GBIC port (sf@0).  The ssd@2200002136bcd49,0 (ssd27) is a disk inside of an A5x00 array.  The long number after the `@' sign is the world wide (unique) number of this particular disk.

Note: sf@0 is the GBIC port on the right and sf@1 is the GBIC port on the left when looking at an I/O with soc+ (socal) board.  On an Enterprise 3000 & 3500, sf@0 is the GBIC port on the bottom and sf@1 is the GBIC port on the top.

/sbus@5,0/scsi@2,0/st@5,0

This device path correlates to an I/O board in slot 2 in the front of a UE server (sbus@5), a SCSI controller card in slot 2 on the I/O board (scsi@2).  The st@5 is a SCSI tape (st) drive at target id 5 attached to this controller.

Without access to the tables above, one is forced to use a different method to determine slot location.

Example:

/sbus@2,0/SUNW,socal@d,10000/sf@0,0/ssd@w21000020370df2a8,0

Divide the "sbus@#" by 2, the remainder is not important.

sbus@2 = Divide the 2 by 2 to reveal the I/O board slot number "2 / 2 = 1" (I/O board slot number = 1)

The device drivers used in this example are some of many device drivers that could appear in the device driver section. See examples below.

E3x00 - only have board slots in the back (internal disks in front)
E4x00, E5x00, E6x00 - have board slots in the front and back

fas - driver for fast/wide SCSI controllers (on-board)
hme - driver for Fast Ethernet
isp - driver for differential SCSI controllers and the SunSwift card
glm - driver for UltraSCSI controllers
scsi - driver for Small Computer Serial Interface (SCSI) devices
sf - driver for soc+ or socal Fiber Channel Arbitrated Loop (FCAL)
socal - driver for SPARC Storage Array (SSA) controllers

This document refers only to device paths for the E3x00 - E6x00 servers. For information about deciphering device paths for the E250 & E450 servers, please refer to infodoc 21216.

rene.vega@East.Sun.COM

I'm including portion of infodoc 18915 below that was combined to create new 22759:
 

How to read an Enterprise Server's device path.

For example:

/sbus@2,0/SUNW,socal@d,10000/sf@0,0/ ssd@w21000020370df2a8,0

sbus@2 = Divide the 2 by 2 to reveal the IO-Board slot number "2 / 2 = 1" io-board in slot# 1

Always divide the "sbus@#" by 2, the remainder is not important (i.e /sbus@7, 7 / 2 = 3 r1).

SUNW,socal@d = "SUNW,socal is the device driver", d is the on-board socal (any other number

would be an sbus slot... 0, 1, 2 also SUNW,fas@3 is always the on-board scsi controller).

sf@0 = GBic location ( 0 = right port, 1 = left port) in an enterprise 3000 & 35000 = bottom 1 = top

ssd@w21000020370df2a8 = The w21000020370df2a8 is part of the disk drive's WWN plus other

information.

The device driver I used in this example is one of many device drivers that could appear in

the device driver section. Some other device drivers are:

SUNW,fas ; SUNW,soc ; SUNW,hme ; SUNW,ffb ; SUNW,isptwo ; ..etc....