what do you mean by "ghost drives"? from what I can tell you have three qcow2 files on a storage, and two of them are attached... though the size seems to be mismatched, maybe try running a 'qm rescan'?
You appear to have two different storages: "NFS-NAS2-Data2" and "bigssd-a". On the NAS one there are three 300G volumes, probably the ones you are looking for. On the VM however, you have configured two drives with 250G and 100G capacity each (actual capacity, as in: these drives really are that size, otherwise the rescan would have yelled) - these are located on "bigssd-a". There's no "ghost drives" anywhere, you just have 5 drives in total, 2 of them configured for the VM and 3 of them unused on some NAS.