Max size HD mount GL-MT300N-V2

Hello I want to buy a new external HD (self powered of course) to connect to my GL-MT300N-V2 (connected to the ISP router). I was able to mount a 2gb usb stick no problem (file sharing using SMB2 on W10) but I am reading of mixed results in mounting large disks (possibly also related to formatting?) So, I can do with a 2TB but I would prefer to buy a 4TB if either the size or the file system (NTFS?) is not a problem for the tiny yellow genius. Anyone with the definitive answer about max size? Thanks!

You’d better use a separated power for your hdd and it should be OK.