If you haven't already, go to Setting up Raspberry Pi - Tools and Services and follow the instructions there. You will need the tools for this tutorial.
This article shows you how to set up a basic NAS using Samba. Keep in mind that this is using a Raspberry Pi 4B 4GB and a usb 3.0 external drive. My read speeds were between 85-109MB/s and my write speeds were between 19-35MB/s. These speeds are fine for streaming videos but will not be sufficient for editing workstations.
Your drives and directories will most likely be different from mine, to make it easier here is a list of my drives and directories that may differ from yours:
Share Directory - /External
External Hard Drive - My_Book_Duo
Partition Assignment - sda2
After installing your Tools and Services you will want to install Samba.
sudp apt-get install samba Next create a directory to mount your drive to. (This is a preference of mine. You can leave your mount point on /media/pi/My_Book_Duo if you want, you'll just want to put the correct path in your smb.conf)
sudo mkdir /External Plug in usb drive and create a folder on the drive called Share.
Now search for the partition assignment your drive will use.
lsblk Unmount your drive so that we can mount it to the /External directory.
sudo umount /media/pi/My_Book_DuoMount to /External.
sudo mount /dev/sda2 /External Now edit your conf file.
sudo vim /etc/samba/smb.conf At the bottom of the file add the following.
[Share]
path = /External/Share
availible = yes
read only = no
browsable = yes
public = yes
writable = yes
create mask = 0777
directory mask = 0777 Create user..
Restart Samba.
sudo service smbd restart You will now be able to find your drive on the network.