Comment # 5 on bug 1169815 from Henk van Velden

That helped!

I never would have thought about it being in a systemd configuration.

I did not want my database to be on /var. For a large database I would have
chosen a directory direct from root (like /database) and then probably on a
separate file system. But it being so small I combined the separate file system
idea with the already separate file system for /home (not vulnarable to system
installations). 

I am not sure why this ProtectHome parameter was invented, nor why it is, from
one moment on the other (that is NOT on new openSUSE version where this could
have been documented in the release notes) without much information given.

Changing defaults (any defaults) is often a very bad thing because many will
have used the defaults by incident and are thus hit hard by something they
didn't ever think of.

I will report this in the forums thread, maybe for the benefit of others.

Thanks for looking into this and providing the solution.