What is a disk image?
A disk image is a complete copy of a floppy disk, including it’s track and sector details, stored in a file. It allows you to store all of the data relating to a particular disk to a file and reconstitute the original disk exactly, at a later time. Amiga emulators use disk images, .adfs, to store a disk’s information and use that disk image as if it were the original floppy disk. That is, within the emulator a disk image is referred to as a floppy disk, inserted and ejected like a floppy disk and read from and written to as if it were a floppy disk. The only difference is that the I/O is actually occurring to or from a file. You can think of the image as a “virtual” floppy drive, if you like. When you’re using Workbench, forget all about disk images. As far as Workbench is concerned it is accessing a floppy disk drive! This is a common misconception amongst emulation and Amiga newcomers. When you’ve finished emulating, the virtual drive can be found as a .
A disk image is a single, large file that faithfully reproduces all of the contents and functionality of a hard disk, optical disk, or other storage device. The disk image might be anywhere from several megabytes to several gigabytes in size, and will end in one of several extensions including .iso, .cue., .bin, or .img. For Macintosh computers, modern disk image files will end in .dmg. If you have copied your favorite music CDs or DVDs, you are probably already familiar with the idea of creating a disk image on your hard drive. One popular program, Nero Burning ROM, uses the .nrg extension for disk image files. Once the image is created from the source disk, it is burned to a blank CD or DVD. This is not the only way to make copies, but it is highly convenient. If the burning process fails, the hard disk image is available for reburning without having to access the source disk again. A disk image is an excellent way to create backups of hard disks, as conventional backup programs can
A disk image file (or simply a disk image) is an exact binary copy of an entire disk or drive. Disk image files contain ALL the data stored on the source drive including not only its files and folders but also its boot sectors, file allocation tables, volume attributes and any other system-specific data. Actually, a disk image is not a collection of files or folders but is an exact duplicate of the raw data of the original disk, sector by sector. Since disk images contain the raw disk data, it is possible to create an image of a disk written in an unknown format or even under an unknown operating system. File formats of disk images usually depend on the type of the source drive. For example, ISO files are CD images; IMG (or IMA) files usually are images of hard, floppy and/or removable disks; and XDF files are always floppy disk images. Disk images are widely used by CD recording software for transferring and storing complete CD contents. A lot of CD recording programs use their own fo
Virtual Hard Disk File: On a physical computer the disk is a disk drive, however on a virtual machine the disk can be one of a few formats: • Dynamically Expanding Virtual Hard Disk • Fixed Size Virtual Hard Disk • Differencing Virtual Hard Disk • Linked Virtual Hard Disk The most common is the Dynamically Expanding Virtual Hard Disk. All of the Virtual Hard Disks are stored as files accessible by the host operating system, the files can be local or anywhere the host can access (file server, SAN, etc.). At the lower levels a hard disk is simply a bunch of sectors, the file system, files, boot records, and anything else are irrelevent to disk drive – As they are irrelevent to the .VHD Files. This is at a lower level than the file system, so the VHD format can store ANYTHING that can be stored on a disk drive, boot sectors, multiple file systems, or anything else. The VHD file format is a standard by Microsoft which other vendors can use, so you will likely see other software support it
