Andy Sparrow writes:
 > 
 > You can't specify the partition to the DEC PROM boot program either. You
 > have to use:
 > 
 > boot 5/rz1/netbsd
 > 
 > E.g. you get to choose the disk, no finer granularity than that, AFAIK :)

I have a document that describes how to boot a 5k from another
partition, but I've never tried it myself.  I had a 2100 for NetBSD at
the time and have used it for subsequent installs, so I never got to try
this out.  Hope it helps/works!

------- Forwarded Message

Date: Wed, 28 Feb 1996 13:43:54 -0500
Message-Id: <9602281843.AA05157@decatl.alf.dec.com>
From: pand::rhett::lacorti (STARS Mail Facility)
To: sandy@decatl.ENET.dec.com
Subject: [ULTRIX] How To Boot From An Alternate Partition On A DS5000

[ULTRIX] How To Boot From An Alternate Partition On A DS5000
********

Copyright (c) Digital Equipment Corporation 1992, 1993. All rights reserved

PRODUCT: ULTRIX V4.X

SOURCE:     Digital Customer Support Center

QUESTION:

How do you specify an alternate partition for booting a DECstation/system
5000?


ANSWER:

The boot command to boot a DECstation/system 5000 from a partition other
than the 'a' partition is undocumented, unsupported and not
guaranteed to work.  However an example on how it might work
follows:


The console command would be -
        >> boot slot_number/rz(device_number)/filename [-a] -bb xxxxxx
where xxxxxx is the logical block address of the beginning of the
alternate partition.  An example is -
        >> boot 5/rz0/vmunix -a -bb 123456
where 123456 is the logical block address of the boot partition.

The 'bootblks' and 'Ultrixboot' files must also be located in the boot
partition.  'bootblks' can be found in the /usr/mdec partition or can
be copied from the boot tape or cdrom.  In any case, it is necessary
to use the dd command to copy the file.  Example:

        dd if=/usr/mdec/bootblks of=/dev/rrz3g conv=sync


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