You should visit the old WiKi, unfortunately the migration to the new wiki hasnt yet finished and major parts are missing. 11.2 has been documented fairly well in the old wiki, including older releases.
Actually it has been possible to do a dup since 10.3, but it wasnt a supported option untilll 11.2.
On my main desktop I have been upgrading since 10.3 and on my laptops since 11.0.
You should visit the old WiKi, unfortunately the migration to the new wiki hasnt yet finished and major parts are missing. 11.2 has been documented fairly well in the old wiki, including older releases.
Actually it has been possible to do a dup since 10.3, but it wasnt a supported option untilll 11.2. On my main desktop I have been upgrading since 10.3 and on my laptops since 11.0.