Moving External Drive to Internal, Unable to Mount

So I'm relatively new to OMV but messed with it a bit on a Raspberry Pi. I had an external drive mounted with Plex running. The Pi was too slow so I've set up an old PC with OMV and moved my external drive to internal. I can see the disk under Physical Disks but it doesn't show up under Filesystems. I would like to be able to mount this NTFS drive without having to wipe it since I've already got a lot of data on there and nowhere to safely move it. Any suggestions?

I can do that for now but I would like to be able to house everything in one case. So if it was formatted to anything other than NTFS would I be able to easily mount it? My main interest in the drive is for SMB and Plex. Beyond that I don't need/want anything else.

Thanks for clarifying. Media is mainly what's stored on my drive. I wouldn't be too upset if it was lost but I've invested a lot of time in ripping, converting, and organizing. I will definitely have to look into expanding my storage.