Haven't done any system integrity checks.
However, there was enough space on this /usr, and yes
the oslevel command did return 4.3.2.0.
We're going to update 2 more servers in January, but I've decided I'm going to hire a person who's going to do it for me.
Maybe he can learn me some things, and I will let you know by then.
Thanks for all your replies,
Erik