
Choose the Create a virtual hard disk now option and click Create.

On the next screen, you’ll need to create a new hard disk for your virtual machine.You have two options to choose from you could either use Dynamically allocated storage which grows as you keep using the storage, or allocate a Fixed-size storage limit that offers faster performance. This portion will only be accessible to your virtual operating system, i.e., Ubuntu in this case. You’ll also need to allocate a portion of your hard disk to the virtual machine.

For instance, if you have 16GB total RAM, allocate 4GB to the virtual machine.

Ideally, you should choose to allocate about a fourth of your PC’s RAM. Allocate Memory size to your virtual machine.
