On Sun, 21 Dec 1997, Armen Babikyan wrote:

> NetBSD/mac68k (and maybe NetBSD in general) does not assign device numbers
> based on SCSI ID, just by order they come in on a SCSI chain. for
> instance, a NetBSD box with root partition SCSI ID #4 would be mounted as
> /dev/sd0, but if a drive with SCSI ID #2 was added, the new drive would be
> /dev/sd0, and the #4 would be /dev/sd1. similarly, your cd drive would be
> /dev/cd0, no matter what SCSI ID it is, because you only have 1 CD drive
> attached.
> 
> The only use of this "feature" (that I can see) would be to be able to
> boot a NetBSD machine without having to know or assign what drive is
> on what device number, as labeled in /etc/fstab on linux systems; the
> machine just mounts the first numbered SCSI device it comes on in the
> chain (which is, on many macs, 0).

Perhaps there needs to be some clarification here...

Linux's /etc/fstab does not do anything more than any other unices'
/etc/fstab.  It does NOT map dev entries to SCSI nexxus/addresse points.

Linux's /dev/sda can be ID0 or ID5 or whatever...their assigned in the
order drives are found on the bus.    SImiliarly, my SCSI cdrom on ID3 is
named /dev/scd0, which has nothing to do with the fstab.

You may be thinking of something that some BSD-based commercial unixes do.
Such as Ultrix:  the devices are named /dev/rz{ID} or /dev/rrz{ID} where
ID is the SCSI ID.   

> of course, this system isn't foolproof; maybe a feature to edit /etc/fstab
> and use the linux system of booting could be used in the future...i don't
> know.

There has been discussions in the Linux groups about using that old style
ID-based addressing, but nothing has been done.
 
Adam

> On Sun, 21 Dec 1997, Marc Coevoet wrote:
> 
> > I have problems mounting a cdrom@scsi id 5.  I saw there
> > are only cd devices for #0 and #1.  I already did a
> > /dev/MAKEDEV cd5
> > and tried
> > mount_cd9660
> > but still get
> > cd9660: not configured..
> > 
> > Anybody?  (I scrolled through mknod/fstab/mount(_cd9660)
> > man pages several times...)
> > 
> > Probably very simple...
> > 
> > Marc
> > 
> > 
> 
> 


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   Adam Fritzler
   afritz@iname.com
   http://www.afritz.base.org
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