Re: Can NetBSD on USB stick force root to be identified as sd0a?

[Dan LaBell <dan4l-nospam%verizon.net@localhost>]

On Jun 12, 2014, at 3:57 AM, Thomas Mueller wrote:

> Is there any way to force a USB installation to identify the root  
> as sd0a, when the disk number would normally be variable?
>
> I could put in kernel config
>
> config netbsd root on sd0a type ffs
>
> but would NetBSD still decide for itself and fail to boot if it  
> decides some other device is sd0?
>
> Or would NetBSD actually recognize boot device as sd0?
>
> Other possibility is to go to BIOS/UEFI and set boot priority with  
> the NetBSD USB installation first.  I haven't tested that yet.
>
> This question is mainly for NetBSD 6.x as opposed to -current,  
> where I could use NAME= with GPT partitioning.
>
> I am practically abandoning NetBSD 5.x, not updating any more,  
> doing very little on 6.x , but have a 6.x USB-stick installation  
> that I might want to update, both i386 and amd64.
>
>
> Tom


On Jun 12, 2014, at 3:57 AM, Thomas Mueller wrote:

> Is there any way to force a USB installation to identify the root  
> as sd0a, when the disk number would normally be variable?
>
> I could put in kernel config
>
> config netbsd root on sd0a type ffs
>
> but would NetBSD still decide for itself and fail to boot if it  
> decides some other device is sd0?
>
> Or would NetBSD actually recognize boot device as sd0?
I had set up as thumb drive as a rescue disk, I had been just doing  
boot -a,
but just tried something I had considered but put off.  In my case I  
set up
as artificially high sd9, since I already have a zip drive as sd0,  
and scsi
controller.
The idea is specify every thing that's a sd I have, and set the thumb  
drive
to a high number, in case something fails etc.
------
# Kernel root file system and dump configuration.
config          netbsd  root on sd9a type ffs

# ATAPI devices
# flags have the same meaning as for IDE drives.
cd*     at atapibus? drive ? flags 0x0000       # ATAPI CD-ROM drives
sd*     at atapibus? drive ? flags 0x0000       # ATAPI disk drives
#st*    at atapibus? drive ? flags 0x0000       # ATAPI tape drives
uk*     at atapibus? drive ? flags 0x0000       # ATAPI unknown

sd0 at atapibus? drive 0

scsibus0 at trm0
sd1     at scsibus0 target 5 lun 0
sd2     at scsibus0 target 6 lun 0

# SCSI bus support
scsibus* at scsi?

# USB Mass Storage
umass*  at uhub? port ? configuration ? interface ?
wd*     at umass?

sd9     at scsibus1 target 0 lun 0
----
Basically, just I just plugged in the thumb drive, typed dmesg
and put the 'at scsibus1 target 0 lun 0' at what seemed like a good  
place.
I don't know how to lock scsibus1 to umass0, but seemed like I didn't  
need to.