Upgrade from OC9.0.6 to NC10.0.1 not starting

I have a Centos7 hosted OC9.0.6 running.

I want to upgrade to NC10.0.1. Therefore I extracted to a different html directory the NC tar archive.

On starting the upgrade with “sudo -u apache occ upgrade” I get “Exception: Updates between multiple major versions and downgrades are unsupported.
Update failed”

Any idea?

OK , I did not delete to original OC9.0.6 directory and files. That is the issue?