To ensure upgrade safety, VyOS uses "binary installation" that allows you to keep multiple images on the same system and switch between them.

Upgrade procedure

Note: If you have a working system, you don't need to boot from the ISO in order to upgrade! The commands given below are to be issued from your current system. The only reason to boot from the ISO is to install VyOS on a new machine.

1. Find the URL for the desired release in release notes or release announcement. (Note: the image file depends on your system architecture. Choosing the wrong architecture can lead to a non-responsive remote device.)
2. Issue the following operational mode command: add system image <image URL>.
3. Answer the installation script questions.
4. [Optional] View images with the show system image operational mode command.
5. Reboot your system.

If the upgrade went wrong

If you can still access the machine console, reboot it and select the previous image from the GRUB menu. Upgrade does not modify existing images and files associated with them, so you will be able to get a working system again.

Config migration

Forwards-compatible configuration syntax changes are handled automatically. In the case a release includes incompatible syntax changes, you may need to edit your config or perform other actions. Check release notes. Releases are assumed to be backwards-compatible unless otherwise specified.

Upgrading from 1.1.x

If you are running a release prior to 1.1.0, it is recommended to first upgrade to 1.1.8 before upgrading to the current release. Upgrading directly from older releases may result in a non-bootable image.

A note on apt-get

Even though VyOS is Debian-based, it does not use apt-get for the upgrade. The only supported upgrade procedure is image-based upgrade described above.

Using apt-get upgrade/dist-upgrade is very likely to render your system inoperable.