Patent attributes
Providing continuous data protection includes maintaining a database having substantially all data modifications made to a primary volume over a recovery interval. The database is maintained in conjunction with a copying operation where the data of the primary volume are mirrored to a remote volume to permit recovery of mirrored data in the event of loss of primary volume data. The contents of the remote volume generally lag behind the contents of the primary volume by substantially the recovery interval. Providing continuous data protection also includes providing data roll-back to a precise point in time within the recovery interval by applying, to the contents of the remote volume, all data modifications in the database that occurred between the latest data modification to the remote volume and the precise point in time within the recovery interval. A time stamp mechanism of sufficient precision and granularity may be used.
