Editing Solaris 10 System Administration Part I (section)

=== Solaris OS device naming conventions ===

Solaris OS uses three different types of names depending on how the device is being referenced
* logical device names
* physical device names
* instance names

==== logical device names ====

logical device names are symbolic links to physical device names in /devices directory

logical devices are primarily used when entering commands on command line

all logical device names are in /dev directory

logical device names contain controller #, target # (if required), disk #, & [slice or fdisk partition #]

every disk has entries in /dev/dsk & /dev/rdsk directories

/dev/dsk is for block disk devices

/dev/rdsk is for character disk devices

==== 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>

==== instance names ====

instance names are shortened names for a physical device

instance names are abbreviated names assigned by the Solaris OS kernel for each system device

instance names are usually used to display on console or in /var/adm/messages log file

Example instance names:
* sd# = SCSI disk name & # is the number, such that sd1 would be 2nd SCSI disk device
* cmdk# = common disk driver is the disk name & # is the number, such that  cmdk0 would be first SATA disk device
* dad# = direct access device name & # is the number, such that dad1 would be 2nd IDE disk device
* ata# = Advanced Technology Attachment (ATA) is disk name & # is the number, such that ata0 would be first 
* qfe# = quad fast ethernet & # is the number, such that qfe2 is 3rd interface on quad fast ethernet device