How do i get more storage in my server

I currently own a Dell poweredge t105 server, basic specs can be found here
In that PDF it says that the Maximum Internal Storage is 2.0TB (2 x 1.0TB) SAS or 2.0TB (2 x 1.0TB) SATA
Since I bought this server a few years ago I have always followed this layout where I have two 1TB drives in the system.

The main question is how can I get more storage in there, could I just simple add more drives or do I have to get a pci card to allow me to put more drives in.
If I just get new hard drives there is 2 open sata connectors on the MB, Im guessing the drives would have to be 2TB of less in size.
If I need a pci card what card is recommended?

Yes you can just link up more drives via the SATA ports on the motherboard. The maximum per drive (from what I can find) is as you state 2TB per drive. If you connect anything larger, it will appear as a 2.2TB drive in the OS.

If you want RAID capabilities then I would advice going and adding something like a PERC RAID controller.
If you want to just connect drives, you could get an LSI 9211 and flash it to IT mode. (Dumbs it to a basic HBA)

If you want to add larger than 2.2TB drives, you will need a different controller. (Such as the LSI 9211 HBA)

Thank you for the reply, that's what I thought it ment I just needed to make sure