$NetBSD: upgrade,v 1.15 1998/05/12 00:00:19 ross Exp $	

The upgrade to NetBSD _VER is a binary upgrade; it can be quite difficult
to advance to a later version by recompiling from source due primarily
to interdependencies in the various components.

To do the upgrade, you must have the boot floppy image (boot.fs)
available.  You must also have at least the "base" and "kern"
binary distribution sets available, so that you can upgrade with it,
using one of the upgrade methods described above.  Finally, you must
have sufficient disk space available to install the new binaries.
Since the old binaries are being overwritten in place, you only need
space for the new binaries, which weren't previously on the system.
If you have a few megabytes free on each of your root and /usr
partitions, you should have enough space.

Since upgrading involves replacing the boot blocks on your NetBSD
partition, the kernel, and most of the system binaries, it has the
potential to cause data loss.  You are strongly advised to BACK UP ANY
IMPORTANT DATA ON YOUR DISK, whether on the NetBSD partition or on
another operating system's partition, before beginning the upgrade
process.

The upgrade procedure using the sysinst tool is basically the
same as an installation, but without the hard disk partitioning.
Another difference is that existing configuration files in /etc
are backed up, and merged with the new files. Getting the binary
sets is done in the same manner as the installation procedure;
refer to the installation part of the document, section 7 and 8,
on how to do this. Also, some sanity checks are done, i.e.
filesystems are checked before unpacking the sets.

After a new kernel has been copied to your hard disk, your
machine is a complete NetBSD _VER system.  However, that
doesn't mean that you're finished with the upgrade process.
You will probably want to update the set of device
nodes you have in /dev.  If you've changed the contents of
/dev by hand, you will need to be careful about this, but if
not, you can just cd into /dev, and run the command "sh
MAKEDEV all".

You must also deal with certain changes in the formats of
some of the configuration files.  The most notable change is
that the "options" given to many of the file systems in
/etc/fstab or by hand have changed, and some of the file
systems have changed names.  To find out what the new options
are, it's suggested that you read the manual page
for the file systems' mount commands, for example mount_nfs(8)
for NFS.

Finally, you will want to delete old binaries that were part
of the version of NetBSD that you upgraded from and have since
been removed from the NetBSD distribution.