NetBSD/distrib/notes/pmax/prep

Currently NetBSD/pmax supports three different installation methods.
From most convenient to least convenient, they are:

	1. Booting as a diskless workstation via Ethernet,
	   followed by initialization of the local disk and
	   installing onto the local disk over NFS.

	2. Copying a bootable diskimage onto the beginning of a disk
	   and installing onto that disk 
	3. installation using a helper machine to set up a bootable
	   NetBSD/pmax  root filesystem, and moving the disk
	   to the target.

Before you start, you must choose an installation method.  If you have
an Ethernet connection to an NFS server that can provide even ~30M for
a diskless-root filesystem, then insatllation via the net is best.
Next best, if your DECstation is already running Ultrix and has two
disk drives (or one, if you live dangerously), is to copy a diskimage
onto one drive.  Finally, you can install by using a second machine as
a helper to prepare a bootable NetBSD/pmax disk.

If your target is going to run diskless, then installation proceeds as for
method 1.

You should examine the guide on the NetBSD/pmax web site, which has
more complete and more up-to-date instructions and tips than are given in
this document.

You should familiarize yourself with the console PROM environment
and the hardware configuration. The PROMs on the older Decstation
2100 and 3100 one syntax. The PROMs on the TurboChannel machines
use a completely different syntax.  Be sure you know how to print
the configuration of your machine, and how boot from disk or
network, as appropriate.

On the 2100/3100, that's
	boot -f rz(0,N,0)netbsd		(boot from rzN)
	boot -f tftp()			(boot diskless via TFTP)
	boot -f tftp()			(boot via MOP from an Ultrix server)

On the 5000/200, the equivalent is
	boot 5/rzN/netbsd
	boot 6/tftp
	boot 6/mop

and on other  5000 series machines,
	boot 3/rzN/netbsd
	boot 3/tftp
	boot 3/mop

You will also need to know the total size (in sectors) and the
approximate geometry of the disks you are installing onto, so that
you can label your disks for the BSD fast filesystem (FFS).  The
system comes with sample disk labels for DEC-supplied SCSI drives.
For third-party drives you will need to get head/sector/cylinder
information.  For newer ZBR drives you can safely make this
information up.



If you're installing NetBSD/pmax for the first time it's a very good
idea to pre-plan partition sizes for the disks on which you're
installing NetBSD.  Changing the size of partitions after you've
installed is difficult.  If you do not have a spare bootable disk, it
may be simpler to re-install NetBSD again from scratch.

If you install by copying a disk image, and you want to change the size
of the root partition from the default 32Mbytes, you will need a second
`scratch' disk. You should copy the diskimage onto the `scratch' disk,
boot the scratch disk, and use it to create a tailored root filesystem.
This is because you cannot change the size of an active partition (i.e.,
the root filesysem you booted). The standard trick to get around this is
to put a cut-down miniroot into the swap partition, boot the miniroot,
and use that system to change the root filesystem size.  DECstation
PROMs don't reliably support booting off partitions other than the 'a'
partition, which is why you need two disks to tailor the root filesystem
size.

Assuming a classic partition scheme with separate root (`/') and /usr
filesystems, a comfortable size for the NetBSD root filesystem partition
is about 32M.  A good initial size for the swap partition is twice the
amount of physical memory in your machine (though, unlike Ultrix, there
are no restrictions on the size of the swap partition that would render
part of your memory unusable).  The default swap size is 64Mbytes, which
is adequate for doing a full system build.  A full binary installation,
with X11R6.3, takes about 130MB in `/usr'.