[OpenBIOS] Decoding Solaris/SunOS disk identifiers?

Mark Cave-Ayland mark.cave-ayland at ilande.co.uk
Wed Aug 7 08:56:47 CEST 2013

On 05/08/13 19:00, Tarl Neustaedter wrote:

> I"m a little rusty on this, haven't done SunOS 4.1.3 since 1993...
> However, I believe the mapping of sd(w,x,y):z correlates directly with
> the Solaris 2.x and later c0t0d0s0 mapping. If so, the fields (in
> Solaris speak) are Controller, Target, Device(lun), Slice.
> The controller number is a pure solaris construct, it's the incremental
> number of SCSI controller accumulated since the OS was installed. That
> is, if you have only one SCSI controller, it will be controller number
> 0. If you have two controllers, the first one it saw the first time is
> controller number zero, and the second one will be controller number 1.
> If you remove one of your controllers (or move it into a different
> slot), the new location will get controller number 2. Yes, this is
> understood as an awful method of tracking device instances, and has
> numerous failings, but we never have managed to move past it.
> The Target will be my-unit phys.hi.
> The Lun will be my-unit phys.lo
> The partition/slice number will be based on how the disk was labeled.
> Slices are named with letters in OBP-land, the first slice being "a". If
> it's UFS, slice "c" is the slice which encompasses the whole disk -
> usually *not* what you want to boot from. It's normally called "backup".

This is exactly what I'm looking for - thanks Tarl. I'll try and code up 
a patch based upon this later today.

Many thanks,


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