[HELP] Using one USB HDD as ROM source and Samba shares.

[Link]

Hello!
I have this new Raspberry Pi 3 B+ and I just installed Retropie. My original plan for this Raspberry Pi is using it for NAS (mounting my 4TB HDD and sharing its content via Samba), but I see in Retropie's guide section, it only covers if the drive is fully committed to Retropie (meaning that I need to format it first before mounting it), and I don't want to format this HDD because it already has my data to be shared via Samba.
So, can I use this HDD as ROM source (running off of it) and Samba share at the same time? If so, how?

[mitu]

@Link The ROMs are all stored in the /home/pi/RetroPie/roms folder, just allocate a partition or a folder on the disc to ROMs and then mount it under the aforementioned folder, making sure it's writeable by the pi user.

[Link]

@mitu Sorry, but I don't understand your steps. Can you provide it in more detail?
And no, I am not ready to partition this HDD yet.

[mitu]

Do you have any experience with Linux ? Did you set up your PI as a NAS server with the HDD ?

[Link]

@mitu Currently, yes. I've set up so /media/usb0 is shared through Samba.

[mitu]

@Link You can create a folder for the ROMs on the /media/usb0 partition, copy the contents of /home/pi/RetroPie/roms to it, then symlink /home/pi/RetroPie/roms to the folder on the HDD. Make sure you create a back of /home/pi/RetroPie/roms first, just in case.

Or you can bind mount the folder over /home/pie/RetroPie/roms with something like

mount -o bind /media/usb0/<Folder_name> /home/pi/RetroPie/roms