Image-based backup is a backup process for a computer or virtual machine (VM) that creates a copy of the operating system (OS) and all the data associated with it, including the system state and application configurations. The backup is saved as a single file that is called an image.
The advantage to image-based backups is that all of the information can be collected in a single pass, providing an updated bare metal restore (BMR) capability with each file-based backup.
Image-based backup products can perform backups online, perform dissimilar hardware restores, enable file-level restores from their image-based backups, recover servers remotely across wide area networks (WANs) or local area networks (LANs) and allow backup images to be saved to a variety of different media. Many products also support encryption.
Because image-level backup applications use snapshots, all of the data, including deleted files and empty disk blocks, are backed up. To reduce the amount of data stored, some vendors are incorporating data reduction technologies such as data deduplication.