Editing Solaris 10 System Administration Part I (section)

==== physical device names ====

uniquely identifies physical location of hardware devices on system

physical device names are located in /devices directory

physical device name contains hardware information, separated by slashes, that represent the path through the system's physical device tree to the device

symbolic links in /dev/dsk & /dev/rdsk point to physical device files, use ls -l

use ls -lL

The use of <code>ls</code> command with -L option will, if file is a symbolic link, evaluate the file info & file type of the file or directory that the symbolic link references, rather  than those of the link itself. However, the name of the link is displayed, rather than the referenced file or directory.

Example:
<pre># ls -l /dev/dsk/c1t1d0s0
lrwxrwxrwx   1 root     root          43 May  3 16:19 /dev/dsk/c1t1d0s0 -> ../../devices/pci@1c,600000/scsi@2/sd@1,0:a
# ls -lL /dev/dsk/c1t1d0s0
brw-r-----   1 root     sys       32,  8 Jul 14 16:50 /dev/dsk/c1t1d0s0</pre>

<insert pic of sample device tree>

Two categories of device trees include devices recognized by hardware at boot time & known by Solaris OS kernel [managed by software controls available to Solaris OS.

If no device file exists for a powered-on & connected physical device then Solaris OS kernel doesn't recognize the device in its device tree

Top directory in hierarchy is called root node of the device tree. The bus nexus nodes & leaf nodes below root object have device drivers associated to them

A device driver is software that communicates with physical device & device driver must be available to Solaris OS kernel so system can use device

During system initialization the Solaris OS kernel identifies physical location of a device. The kernel relates a node with an address [nodename@address] which is the physical device name

<insert pic of example>