When creating virtual machines with Hyper-V, there are additional considerations that you must take when storing virtual machine configuration. A common misconception is that the virtual machine configuration is only the xml file that contains the hardware configuration for the VM. The remainder of the configuration also includes two files, which will add to the necessary disk space requirements.
So what are these files used for? The .bin file is used to allocate enough space to store the contents of memory for the virtual machine , should the VM need to be saved, and will be the size of memory defined for the child partition.
The .vsv file is our saved state for devices. When booting a virtual machine 20 MB is reserved for the .vsv. When placing the virtual machine into a saved state, this file may shrink or may grow upwards to 50 MB depending on the number of devices configured for the virtual machine.
The default location for storing virtual machine configuration is C:\ProgramData\Microsoft\Windows\Hyper-V\Virtual Machines, but this is configurable via Hyper-V Settings in Hyper-V Manager.