Q: Some of my Hyper-V virtual machines have a BIN file and some don't; why?
A: The BIN file created in the virtual machine folder of the virtual machine is equal to the size of the memory of the virtual machine and is a space placeholder to save the virtual machine state in the event that the Hyper-V host is shut down. So why don't all virtual machines have a BIN file equal to the size of the virtual machine memory? It depends on the configuration of the virtual machine. By default, all virtual machines have an Automatic Stop Action of Save, which means the state of the virtual machine is saved to disk, hence the BIN file. However, the best practice is once Integration Services are enabled the Automatic Stop Action should be changed to Shut down the guest operating system, which performs a clean shutdown and no longer needs the BIN file to save the memory content to. This is why some virtual machines have the large BIN files and some don't. Virtual machines still using the default Save the virtual machine state Automatic Stop Action will have the BIN file.