22 Nov
2017
22 Nov
'17
3:24 p.m.
On Tue, Nov 21, 2017 at 01:52:54PM +0000, Giles Orr via talk wrote:
As a short follow-up: current VirtualBox does use some form of expandable file system for its disk images (.vdi files), but if they're sparse files, they're hidden inside the image file somehow (I could have researched the VDI file format ... but I didn't. Not the point right now). I have quite a number of VDI images that are 8GiB in use, but on disk they're 1-3Gib and use the same amount of disk space as their file size.
Some virtual machine disk formats are dynamically allocated as part of their own format. Some (like raw disk images that you can use with qemu and some others) are usually just sparse files that get allocated as needed. -- Len Sorensen