On my server, PC and Mac… where’s it all gone? What am I going to do?

I think I need to buy some bigger disks and put them in my server. A terabyte should do me. My PC needs its disk sorting out, there’s Linux and Windows squashed in there, along with a data partition. Then I installed a few virtual machines in Windows and now the Windows partition is full.

If I can offload the data partition onto my server, that can be used for virtual machines instead.