Are you using the SolVe Desktop (URL: < https://solve.emc.com/desktopbinaries/setup.exe >) to generate procedures which will direct you with what to backup?

It will provide a thorough process to follow for the update.

You should have a current bootstrap backup.

This is also true for the indexes but these are not elementary.

And do not forget to read the docs. If you NW version is to old, you might need to upgrade to an interin version.