I did some further testing with hard disks. As said, Ubuntu 16.04.1 didn't have these problems with the same hard disk that Ubuntu 18.04.1/20.04.1 had.
However, this wasn't about hard disk itself. This was about the file system. The problems arise when using NTFS-filesystem. With the normal Ubuntu filesystem, ext4, everything works fine.
I also tested with a SSD-disk connected to USB-3 interface. It works fine and is rather quick, with ext4 filesystem, as it should be. This is important, because that is the way how to use a larger number of VMs on a laptop, where internal disk space is always limited. On a workstation, you have other options.
I cannot speculate where this problem arises: 1. Ubuntu distro (works in 16.04.1, not in later versions), 2. Linux kernel (also Fedora is affected), or 3. VMware implementation (the disk itself works fine with files, copying 110 GB VM works always as expected).
If you have more information, I am interested. As such, this problem is solved for me.
