For some reason Ubuntu decided not to utilize the 100GB I cleared for it, and installed itself with only 28GB of space. I only discovered this now, after it started bugging me about running out of space.
I've tried googling my issue, but it appears that it's a somewhat dangerous process that heavily depends on the exact situation, so I thought I'd be better off asking you guys for help.
I have two physical drives, one for Windows only and another for storage/Ubuntu. The partitions on the second drive looks like this.
