This technology is commonly known as Snapshot and is often associated with a backup application, if possible to a remote site from where the data have been replicated. From the moment the snapshot has been created, original data are copied into the snapshot volume before being modified on the production volume. The snapshot volume is progressively filled as well as writing operations are generated on the production volume until it is filled or destroyed. The application reads and writes seamlessly on the volume of production, the backup application has a read-only acces to the volume of data containing the original data. It may be possible to keep snapshot online to accelerate the restoration process which can be slow depending on the relevance of data to restore.

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