Virtual hard disk files store information such as the operating system, program files, and data files. They are named <VM-NAME>.vmdk (for example, Ubuntu_VM.vmdk for a virtual machine named Ubuntu VM). Virtual hard disk files can be configured as either IDE or SATA disks for the guest operating system. If the guest operating system has a driver for the LSI Logic or BusLogic SCSI adapter, a virtual disk can also be configured as a SCSI disk.
The files that make up IDE, SATA, or SCSI virtual hard disks can be stored on IDE, SATA, or SCSI hard disks, or any other type of fast-access storage media. IDE and SCSI virtual hard disks can be up to 8TB. Each virtual hard disk can be stored in one or more files, depending on the size of the virtual hard disk and the host operating system. By default, the actual files that the virtual hard disk uses start small and grow to their maximum size as needed, but they can also be configured so that all of the disk space is allocated when the virtual disk is created.
You can also configure a virtual hard disk to use a set of files limited to 2GB per file, which can be useful if you plan to move the virtual hard disk to an older file system that does not support files larger than 2GB.