Subject: Re: Dynamic SCSI ids (was: A possible way of handling...)
To: None <tech-kern@NetBSD.ORG>
From: Ignatios Souvatzis <ignatios@cs.uni-bonn.de>
List: tech-kern
Date: 03/29/1997 11:07:38
   From: joda@pdc.kth.se (Johan Danielsson)
   Date: 29 Mar 1997 04:02:50 +0200

   "Chris G. Demetriou" <cgd@cs.cmu.edu> writes:

   > It does the "right thing" in most "simple" environments

   It does the right thing if you never change your scsi setup. The other
   approach (to name devices after scsi-id rather than after the order
   they are detected) also works in these simple cases.

No, it doesn't. 

On the contrary, the BSD approach is, e.g., useful for installation
setups: it will always find a single disk 0, at whatever target id it
is.  

   The BSD-approach fails when you move, add or remove units from *any*
   chain.

Oh... not really.

At home, I tend to put my root disk at target 0 anyway, to have a
stable singleuser boot with GENERIC kernels. 

Would I not do kernel development, I would just wire my normal disks
in the config file, and leave a wildcard entry for changing ones.

If you want to hardwire your disks, you can do it with

sd0 at scsibus? target 0 lun 0
sd1 at scsibus? target 1 lun 0
...
sd7 at scsibus? target 7 lun 0

pretty easily. But what would you do with a disk on a 2nd scsibus?

Btw, what _you_ really would want isn't a mount by physical attributes
like target id (you could change jumpers in between boots as easily as
remove the disk logically in front) but mount by volume name. 

	Ignatios Souvatzis