To do the upgrade, you must have some form of bootable media (CD-ROM, USB drive, floppy, etc.) available and at least the base and kern distribution sets. Since files already installed on the system are overwritten in place, you only need additional free space for files which weren't previously installed or to account for growth of the sets between releases. Usually this is not more than a few megabytes.

The upgrade procedure is similar to an installation, but without the hard disk partitioning. sysinst will attempt to merge the settings stored in your /etc directory with the new version of NetBSD. Also, file systems are checked before unpacking the sets. Fetching the binary sets is done in the same manner as in the installation procedure.

Before doing an upgrade it is essential to read the release information and upgrading notes in one of the INSTALL files: this is the official description of the upgrade procedure, with platform specific information and important details. It can be found in the root directory of the NetBSD release (on the install CD or on the FTP server).

It is advisable to print the INSTALL document out. It is available in four formats: .txt, .ps, .more, and .html.

The following section provides an overview of the binary upgrade process. Most of the following sysinst dialogs are similar to those of the installation process. More verbose descriptions and explanations of the dialogs are available in Chapter 3, Example installation.

After selecting the installation language and the keyboard type, the main menu appears. Choosing option “b: Upgrade NetBSD on a hard disk” will start the the upgrade process.

The dialog in Figure 4.2, “Continuing the upgrade” will request permission to continue with the upgrade. At this point nothing has been changed yet and the upgrade can still be cancelled. This is a good time to ask yourself whether you have made a backup, and if you know for certain that you will be able to restore from it.

After choosing to continue with “Yes”, the next dialog will ask you to specify the hard disk with the NetBSD system that shall be upgraded.

The system used for the example has only one hard disk available: “wd0”.

At this point, sysinst will perform a check of the file system to ensure its integrity.

The next step is to choose which type of bootblocks to install.

The following dialog provides a menu to choose the installation type. The choices are “Full installation”, “Installation without X11”, “Minimal installation”, or “Custom installation”.

The following dialog asks for the install method of choice and provides a list of possible options. The install medium contains the new NetBSD distribution sets. You will be prompted for different information depending on which option you choose. For example, a CD-ROM or DVD install requires you to specify which device to use and which directory the sets are in, while an FTP install requires you to configure your network and specify the hostname of an FTP server. More details can be found in Section 3.11, “Choosing the installation medium”.

sysinst will now unpack the distribution sets, replacing your old binaries. After unpacking these sets, it runs the postinstall(8) script to perform various system cleanup and configuration update tasks. If postinstall produces errors, you will have to manually resolve the issues it brings up. See postinstall's man page for more information. Even after a successful postinstall run, it is advisable to use etcupdate(8) to aid in merging any other configuration changes. You should also read the remarks in INSTALL about upgrading, as specific compatibility issues are documented there.

When you are back at the main menu, remove the boot medium (if applicable) and reboot. Have fun with your new version of NetBSD!