Solaris device naming

Solaris device naming

[Michael French]

         I have been using Linux for several years and feel pretty 
comfortable with device naming conventions for most things.  I have 
recently started using Solaris quite a bit more (sigh....).  I am trying to 
understand naming conventions for devices such as hard disks, cds, 
floppies, ethernet, etc. and have not found a good concise source yet.  I 
am reading a Solaris 8 admin book and have gotten about 150 pages into it 
and have not found much on it yet.  Why does Solaris use 
/dev/dsk/c0t0d0s6.  I understand that it is in the dsk dir because it is a 
hard disk and that it is the 6th scsi partition, but what does the other 
stuff represent?  What is the logic behind it?  Any help to some good docs 
or a short description here would be appreciated.  Thanks!

Cheers,


Michael French
Asheville Citizen-Times
IT Dept.
(828)236-8966

Re: Solaris device naming

[Hannu Hirvonen]

On Thu, Apr 11, 2002 at 02:18:16PM -0400, Michael French wrote:
>                                     Why does Solaris use 
> /dev/dsk/c0t0d0s6.  I understand that it is in the dsk dir because it is a 
> hard disk and that it is the 6th scsi partition, but what does the other 
> stuff represent?  What is the logic behind it?  Any help to some good docs 
> or a short description here would be appreciated.  Thanks!

 c0 = controller 0 (i.e. first SCSI controller)
 t0 = target (SCSI ID) 0
 d0 = device 0 (SCSI sub-device)
 s6 = slice (partition) 6

-- 
    Q: "Why is television called a medium?"
    A: "Because it is neither rare nor well-done."

Re: Solaris device naming

[Michael Salmon]

--On Thursday, April 11, 2002 14:18:16 -0400 Michael French 
<mfrench@ashevillemail.com> wrote:
>          I have been using Linux for several years and feel pretty
> comfortable with device naming conventions for most things.  I have
> recently started using Solaris quite a bit more (sigh....).  I am trying
> to understand naming conventions for devices such as hard disks, cds,
> floppies, ethernet, etc. and have not found a good concise source yet.  I
> am reading a Solaris 8 admin book and have gotten about 150 pages into it
> and have not found much on it yet.  Why does Solaris use
> /dev/dsk/c0t0d0s6.  I understand that it is in the dsk dir because it is
> a hard disk and that it is the 6th scsi partition, but what does the
> other stuff represent?  What is the logic behind it?  Any help to some
> good docs or a short description here would be appreciated.  Thanks!

Strictly speaking Solaris doen't use the devices under /dev, it uses the 
/devices directory instead. That is pretty easy to understand, you have a 
direct connection between physical addresses and /devices paths.

The /dev paths come from SVR4, the C stands for controller, more or less, 
the T means target or address on that bus, the D means device which is the 
LUN and the S stands for slice or partition. BTW, s6 is the 7th partition. 
Once a disk has been assigned an address it doesn't change which is usually 
good except when it is an FC disk as the /devices path includes the WWN, 
sigh.

Unfortunately there is no way to tell which disk corresponds to c0t0s0d0 
without following the links. The C numbers are assigned cronologically as 
disks are found in the system, however as the root disk controller is 
always found first it is always c0, not much else is certain.

You can try <http://sunsolve.sun.com>, <http://docs.sun.com>, 
<http://soldc.sun.com> and <http://www.sunhelp.org> for more information. 
Somewhere on soldc there is a document on interpreting /devices.

/Michael
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