Disk Utilities freezes while partitioning

[wannesv]

I'm trying to make a new partition on my macbook pro, but for some reason it's more difficult then what the internet tells me. I select my harddrive, add a partition of 40GB, leaving 40GB free space for my main partition. Now when I press Apply after a while the progress just freezes at 'resizing disk', but the color of the progress bar is still animating so it's not really the program that freezes.
On every video and article I've seen partitioning takes around 2-3 minutes max, while I'm sitting here for 3 hours without even completing 1/3 of the progress.

I could really use some help, if it's possible

 

[Intell]

Whatever you do, don't stop it. It's moving your data around so that all of it is on one half of the disk. The videos are usually done on fresh systems or systems that have large amount of free space.

 

[wannesv]

Whatever you do, don't stop it. It's moving your data around so that all of it is on one half of the disk. The videos are usually done on fresh systems or systems that have large amount of free space.

I have to admit my laptop isn't as fast as it used to be, but I thought 3 hours was still way to long.
Guess I'll let it work overnight and see what the outcome is.

[EDIT]
Seems like an overnighter did the trick, took way longer then I thought.
Now for some reason I don't see the partition while I hold the option key while rebooting.
And here I was thinking it would all be simple