Abstract: A method and system for generating a snapshot in a consistent state is disclosed. The system comprises a host computer, a primary data storage, a data protection unit, and a secondary data storage. The data protection unit monitors a state of an email application which is running on the host computer. The data protection unit generates a snapshot of data stored in a primary data storage when the email application is in a consistent state, and stores the snapshot on a secondary storage. In the event of a system failure, the data is recovered using the last snapshot. A method and system for recovering email data from a snapshot in a consistent state using a client is also disclosed.

Abstract: A method and system for generating a snapshot in a consistent state is disclosed. The system comprises a host computer, a primary data storage, a data protection unit, and a secondary data storage. The data protection unit monitors a state of an application which is running on the host computer. The data protection unit generates a snapshot of data stored in a primary data storage when the application is in a consistent state, and stores the snapshot on a secondary storage. In the event of a system failure, the data is recovered using the last snapshot.

Abstract: A method and apparatus for managing backup data is disclosed. A data backup system defines a plurality of time windows for creating and maintaining backup data in accordance with a data backup policy. Each of the time windows is assigned a predetermined amount of storage space. When the data backup system creates backup data, the system determines whether a storage space assigned to a time window is large enough to accommodate new backup data. If the storage space is large enough, the new backup data is stored. However, if the storage space is not large enough, the system deletes the oldest backup data until enough storage space is obtained.

Abstract: A method for synchronizing a secondary volume with a primary volume in a continuous data protection system begins by scanning a region of the primary volume, which is then compared with a corresponding region of the secondary volume. An identification of the scanned region is stored in a compare delta map when the comparison results in a discrepancy between the scanned region and the corresponding region. Data is copied from the primary volume to the secondary volume, using the compare delta map as a guide to locate the data to copy. If the data protection system has failed just prior to the restore process being initiated, it is termed a re-baseline, and the entire primary volume is scanned. If the data protection system is active prior to the restore process being initiated, it is termed a re-synchronization, and is optimized by scanning only select regions of the primary volume.

Abstract: A method and system wherein data is structured so that writes may be continuously duplicated and a protected volume may be restored to a particular point in time as desired. Writes are continuously duplicated on a secondary volume and organized into delta maps. The delta maps indicate which memory blocks were written to during a particular time frame.

Abstract: In a continuous data protection system having a primary volume and a secondary volume, a method for data recovery begins by selecting a snapshot of the primary volume to be recovered and a location on which the snapshot is to be loaded. A point in time (PIT) map is created for the selected snapshot, and the selected snapshot is loaded at the selected location. A data block from the PIT map is resolved to determine which block on the secondary volume is presented as being part of the snapshot. The snapshot is accessed via a host computer as if the snapshot was the primary volume at an earlier point in time, corresponding to the time of the selected snapshot.

Abstract: A method for browsing objects on a protected volume in a continuous data protection system begins by displaying a list of top-level objects to a user who selects a top-level object to browse. A snapshot is selected from the selected top-level object and is decoded. A list of objects in the selected snapshot is displayed and the user selects an object to browse. The selected object is decoded and operations are performed on the selected object. The user can browse the protected volume by snapshots in the top-level object or by a range of time of coverage of the top-level object.

Abstract: A method for adding redundancy to a continuous data protection system begins by taking a snapshot of a primary volume at a specific point in time, in accordance with a retention policy. The snapshot is stored on a secondary volume, and the snapshot is cloned and stored on a third volume. The cloned snapshot is eventually expired according to a cloning policy.

Abstract: A method and system where data is maintained in a continuous data protection system is disclosed. A primary volume may be protected according to an any-point-in-time (APIT) window wherein restores may be performed at any time as desired. The APIT window may be of any time duration as desired. Outside of the APIT window, a retention policy for phasing out data may be established as desired.