Application-Consistent Backup

An Application-Consistent Backup is a backup that ensures data is not only copied technically but saved in a state that is logically consistent for the respective application. This is relevant above all for databases, ERP systems and other transaction-intensive applications.

The difference lies in the backup moment: a crash-consistent backup freezes the state as it currently resides on the storage – including open transactions and unwritten buffers. An application-consistent backup informs the application beforehand: transactions are completed, buffers are written, and only then is the backup created. Technically, this is done via Microsoft VSS in Windows environments, for example, or via pre-/post-scripts and native database interfaces. The result can be used directly without lengthy repair and recovery runs.

Application consistency is thus a quality requirement for backups, not a convenience feature: it decides whether a restore leads to a usable system or to a corrupt data set. In backup policies, it is therefore one of the basic specifications of resilient Data Management.