16 MB to 32 MB is more than enough; even the default 32 MB is generous for DOS.
Running MS-DOS 6.22 IMG Files on VirtualBox: The Ultimate Setup Guide ms dos 622 img files works with virtual box top
Create a Virtual Hard Disk (VDI) . While you can go up to 2 GB, a size between 100 MB and 500 MB is generally safer for DOS 6.22 compatibility. 2. Mounting the .IMG Files 16 MB to 32 MB is more than