Learn NetBSD - Installation & Partitioning (sysinst)

#Introduction

In episode 2 we understood NetBSD's architecture — the base system, modular kernel, build system, and development flow. Now it's time to pour that understanding into a living system: in this episode we'll perform a NetBSD installation from scratch using sysinst, the text-based installer that is the gateway to your first NetBSD system.

Installation is the most complete exercise because it brings together almost every concept: choosing sets (which make up the base system), preparing the disk (which we met in episode 2 as the foundation of the filesystem), and initial network configuration. If episodes 0-2 were theory, this episode is your first battle. Let's start by setting the stage.

#Before You Begin: Boot Preparation

You'll need the NetBSD 11.0 installer image for your VM's architecture — from episode 0 we've already downloaded and verified it. On the virtual machine, make sure the settings are as follows:

Boot from the installer ISO, and you'll be greeted by the NetBSD boot menu. Choose the Install NetBSD to hard disk option. After a moment, you'll reach the main sysinst menu:

Welcome to sysinst, the NetBSD installation program.
 
a: Install NetBSD to hard disk
b: Upgrade NetBSD on a hard disk
c: Re-install sets or install additional sets
d: Utility menu (fdisk, disklabel, mbr, cvs, ...)
e: Run a shell

Choose a for a new installation. Next, sysinst will ask about the keyboard layout — pick the one that suits you — and then we get to the heart of the matter: disk partitioning.

#Disk Partitioning: fdisk & disklabel

NetBSD separates partitioning into two layers you need to understand:

1. fdisk — MBR/GPT partitions at the BIOS/EFI level that are recognized by the firmware and other operating systems. NetBSD usually occupies one slot here.
2. disklabel — BSD-level partitions inside that slot, which will hold the NetBSD filesystems and swap.

A simple analogy: fdisk is like dividing a plot of land into parcels (for NetBSD and other OSes), while disklabel is dividing NetBSD's parcel into rooms (root, /usr, /var, swap, and so on).

#The fdisk Step

On the Install NetBSD to hard disk screen, select the target disk (usually wd0 for IDE disks or sd0 for SCSI/SATA disks). Sysinst will offer to set up the fdisk partition. If you're using the whole disk for NetBSD, choose Use the whole disk:

Disk: wd0
a: Use the whole disk for NetBSD
b: Use a partition of the disk for NetBSD
c: Edit the MBR partition table
d: Use the existing MBR partition table

Option a is the fastest for a learning VM: one MBR partition spanning the whole disk, with the NetBSD disklabel arranged inside it.

#The disklabel Step

Once fdisk is done, sysinst opens the disklabel editor. This is where you decide the filesystem layout. A simple recommended layout for a server:

Sysinst can create a default layout automatically — for learning, use the default it offers. Here's roughly what you'll see:

Partition  Mount      Size       New File system
a          /          1948M      FFS
b          swap       996M       swap
e          /usr       1992M      FFS
f          /var       1992M      FFS
g          /usr/pkg   1992M      FFS

Choose Set sizes and let sysinst calculate automatically, or set it manually if you already understand your needs. Once you're happy with the layout, continue.

#Filesystem: FFS

NetBSD's default filesystem is FFS (Fast File System), the heir to the BSD tradition that now adopts many UFS2-style features. Sysinst will format the partitions with FFS automatically. You just need to make sure every partition you'll use gets a filesystem — in the table above, the New File system column shows FFS for all partitions except swap.

#Choosing the Sets

The next part is choosing the sets — the collection of files that make up the system. These sets are the base system we discussed in episode 2. The common options:

To follow this series, make sure base, comp, and man are selected — you'll need the compiler and build tools starting in episode 4 (pkgsrc) and 10 (build.sh).

Set selection:
[x] kern-GENERIC   Kernel
[x] base           Base system
[x] comp           Compiler and build tools
[x] man            Manual pages
[ ] games          Games
[ ] xbase          X11 base

Use the space bar to toggle selections, then continue. Sysinst will copy and extract the sets from the installation media.

#Network Configuration

After the sets are installed, sysinst offers network configuration. For a VM with DHCP, choose DHCP — sysinst will detect the interface (e.g. wm0 or virtio0) and obtain an address automatically:

Select network configuration:
a: Automatic configuration (DHCP)
b: Manual configuration
c: No network configuration

If you choose manual, you'll be asked to fill in the IP address, netmask, gateway, and DNS. Whichever you pick, this configuration is later stored in /etc/rc.conf — and in episode 8 we'll dissect it in depth.

#Set Hostname & Root Password

Two last steps before the extraction completes: set the hostname (e.g. nbsd11) and set a root password. Be sure to choose a strong password — root is the most powerful account on the system, and in episode 15 we'll secure it further.

#First Boot

When sysinst finishes the installation, reboot the machine and boot from the hard disk. If everything went well, you'll see the NetBSD kernel boot log ending in a login prompt:

NetBSD/nbsd11 (console) login: root
Password: ******

After logging in, verify that the system is truly alive:

uname -a
sysctl kern.version
df -h
swapctl -l

NetBSD nbsd11 11.0 NetBSD 11.0 (GENERIC) #0: Thu Jul 30 12:00:00 UTC 2026
Filesystem            Size   Used  Avail Capacity   Mounted on
/dev/wd0a             1.9G    84M   1.7G     5%     /
/dev/wd0e             1.9G   1.0K   1.8G     0%     /usr
/dev/wd0f             1.9G   1.0K   1.8G     0%     /var

Notice the Mounted on column: /, /usr, and /var are separate — exactly like the disklabel layout we defined. Your first system is up and running.

#Closing

In this episode 3, you've performed a complete NetBSD installation through sysinst: partitioning the disk with fdisk and disklabel, selecting the base/comp/man sets, configuring the network, setting the root password, and successfully booting into your first NetBSD 11.0 system.

Key takeaways:

• fdisk partitions the disk at the BIOS/EFI level; disklabel divides NetBSD's portion into partitions for filesystems and swap.
• Sets determine the contents of the base system — base, comp, and man are required.
• The default filesystem is FFS; swap is created as a disklabel partition.
• The disk layout is written to /etc/rc.conf (network) and /etc/fstab (mounts) — we'll dissect both files in episodes 6 and 7.
• Verify the installation with uname -a, df -h, and swapctl -l.

In the next episode, episode 4, we'll enter the world of software: package management with pkgsrc and pkg_add — how to install binary packages, build packages from source, and manage dependencies with pkg_info, pkg_admin, and pkg_chk. Make sure your NetBSD system is alive, because the next episode is full of commands! See you in episode 4!