Volume Shadow Copy: A Volume Shadow Copy Service-based backup (VSS-based backup) is a Windows service that captures and creates snapshots called shadow copies. VSS, also known as Volume Snapshot Service, operates at the block level of the file system and enables virtual server backup in Microsoft environments. VSS has three components: Requestor—The application that requests the creation of a shadow copy. Provider—The interface that provides the functionality to actually make the shadow copy. Writer—Application-specific software that acts to ensure that application data is ready for shadow copy creation. Requestors, providers, and writers communicate in the VSS framework to create and restore volume shadow copies. A shadow copy of a volume duplicates all the data held on that volume at one well-defined instant in time. A requestor initiates the backup and restore processes. The provider controls the processes and instructs a writer to prepare a dataset for backup. Wh...