What is the difference between a fixed-size and dynamically-expanding virtual hard disk (VHD)?
Both fixed-size and dynamically expanding virtual hard disks have a maximum size setting that determine how large the disk will appear to the guest OS. The different is that fixed-size disks will take up the entire maximum size of the disk on the host file system while dynamically expanding disks will start small and grow as space is needed. Dynamically expanding virtual hard disks provide the advantage of more efficiently using disk space on the host. So why would you want to use a fixed-size one? The main benefit is performance. Since there’s no overhead related to expanding the physical VHD file, disk access can be significantly faster and disk fragmentation is often reduced. In addition, you don’t have to worry about accidentally running out of physical disk space on the host (which can cause your guest operating system to crash). If these benefits aren’t all that important to you, then stick with dynamically expanding VHDs. And, rest assured: You can always convert between these t
