Instead of using dynamic disks, opt for fixed disks ( Figure A) and give the disk plenty of space.
Why? Because as you use space on a dynamically allocated virtual hard disk, VirtualBox must accommodate and adjust the VM's storage space, which causes the performance to take a hit. However, the dynamically allocated disk is not nearly as efficient as the fixed disk. This makes sense, especially when you are limited in space and aren't certain how much space you'll need for your VM. Generally speaking, when we allot storage space for our VMs, we stick with the default dynamically allocated disk types.
