Abstract: A continuous data protection system, and associated method, for point-in-time data recovery. The system includes a consistency group of data volumes. A support processor manages a journal of changes to the set of volumes and stores meta-data for the volumes. A storage processor processes write requests by: determining if the write request is for a data volume in the consistency group; notifying the support processor of the write request including providing data volume meta-data; and storing modifications to the data volume in a journal. The support processor receives a data restoration request including identification of the consistency group and a time for data restoration. The support processor uses the data volume meta-data to reconstruct a logical block map of the data volume at the requested time and directs the storage processor to make a copy of the data volume and map changed blocks from the journal into the copy.

Abstract: The invention transforms source data from a source platform to a target platform with a single copy. A data request signal is communicated from the target platform to the source platform and a location of the source data is determined in a disk subsystem supporting snapshot. The disk subsystem (i.e., a snapshot facility) copies the source data in raw form to one or more target disks designated by the target platform. The locations of the source data and the target disks are communicated to the target platform and the source data is read from the disk subsystem to transform the data to the target platform. The process starts from a request of an application resident within the target platform. One or more data management units can be used to determine source and target disk locations. Preferably, the source platform also communicates metadata to the target platform; and thus metadata, when available, is also copied via snapshot operations in the disk subsystem.

Abstract: This file server system appears to the host computer to be a plurality of data storage devices which are directly addressable by the host computer using the native data management and access structures of the host computer. The file server however is an intelligent data storage subsystem that defines, manages and accesses synchronized sets of data and maintains these synchronized sets of data external from the host computer system's data management facilities in a manner that is completely transparent to the host computer. This is accomplished by the use of the snapshot application data group that extends the traditional sequential data set processing concept of generation data groups.