I am going to show you how to get the physical disk size for every disk in your system.
First, open a shell so you can access the command line (CLI). If you are on a server, you should already be there, unless you installed a GUI.
With the CLI ready, there two great commands you can use. They are:
fdisk -l | grep Disk
Use either or both of those commands to get the disk sizes. If you get a “permission denied” message, just put sudo front of the command.
I hope that helps!