OpenBSD maintenance: OS reinstall

OpenBSD maintenance: OS reinstall - Jan 22


The official documentation says:

If you have a running OpenBSD system, bsd.rd is all you need to reinstall or upgrade to a newer version.

This post shows how to use bsd.rd above, the ramdisk kernel, to reinstall the OS without network or external media.


Reboot the machine, enter /bsd.rd (or just bsd.rd) when boot> is shown.
Well, remember the boot process will go on automatically in a short while if you don't enter anything.

openbsd booting

That's it !! You will see the installer start.

openbsd ram disk kernel installer


After installing OpenBSD once, bsd.rd is in your hands.
With it, you can reinstall the machine. You can also apply full disk encryption via the shell beforehand. No network or external media is required.