create a new file system

I have just installed 5.0.7 of openserver and forgot to create a /u filesystem.
I have a root filesystem that takes up most of the hard disc space and I want to reduce the size of that and create a /u.
I have tried divvy amd mkdev fs but to no avail.
Could somebody give me some idea as to how I can achieve this please?

regards

Why not just leave it? At this point, you are just looking at many hours of work.

Yes, it wouldn't work since most of the space is in /. Lucky you didn't trash the whole thing.

Two options - start from scratch (wipe it all out and reinstall remembering to put in /u)
or
back it all up to tape, wipe it all out, create a / with less space, create your missing /u, and try to restore to the correct filesystems.

since its a fresh install, theres not much harm in just starting from scratch. IMO.