Comment # 5 on bug 964654 from Dominique Leuenberger

(In reply to Hannes K�hnemund from comment #2)
> I cannot change those settings with "yast2 lan", see screenshot. Seems that
> NetworkManager is handling it ...

Yast says it "can't configure *SOME* settings" - The hostname is not amongst
the settings it can't manage for you.

Klick OK, change to the tab Hostname/DNS and you will see that the part for
settings the hostname is NOT grayed out.. and can be configured.

alternatively, you can use
> hostnamectl set-hostname <NAME>

Please verify and report back