This is, in my experience, a major pain point of VirtualBox that I don't see why Oracle apparently doesn't care about, despite being aware of the issue since at

This is, in my experience, a major pain point of VirtualBox that I don't see why Oracle apparently doesn't care about, despite being aware of the issue since at least 2017. We're stuck in a situation where fixed-size disk images are too large to use if you care about your host's disk space (unless they're created with an "almost full" target usage), and dynamic sized images tend to grow to unwieldy sizes unless you regularly zero-out empty spaces from the guest (cat /dev/zero >somefile on Linux, sdelete -z C on Windows IIRC), then VBoxManage modifyhd --compact the image from the host once the VM is off. But it shouldn't be this way. VirtualBox added support for TRIM years ago, and guest OSes could very well happily live inside dynamic images - if it worked at all. In practice (AFAIK, for the few who ventured to use it) - it doesn't work: https://www.virtualbox.org/ticket/16795 https://www.virtualbox.org/ticket/16795