Abstract: A flexible witness service system architecture is provided that comprises one or more cluster sites each having at least two storage/compute nodes; at least one local external device associated with at least one of the one or more cluster sites, the at least one local external device configured to run a local witness service. A central cloud management platform is in communication with the one or more cluster sites, the central cloud management platform being configured to run a cloud witness service. The local witness service and the cloud witness service perform identical arbitration services if a storage/compute node in one of the one or more cluster sites fails or communication between storage/compute nodes in a cluster fails.

Abstract: A flexible witness service system architecture is provided that comprises one or more cluster sites each having at least two storage/compute nodes; at least one local external device associated with at least one of the one or more cluster sites, the at least one local external device configured to run a local witness service. A central cloud management platform is in communication with the one or more cluster sites, the central cloud management platform being configured to run a cloud witness service. The local witness service and the cloud witness service perform identical arbitration services if a storage/compute node in one of the one or more cluster sites fails or communication between storage/compute nodes in a cluster fails.

Abstract: A method and system of providing a virtual transport session is disclosed. According to one embodiment, a virtual transport session is provided by establishing a virtual transport session between an initiator module and a target module across a network, wherein the virtual transport session comprises a transport session. Thereafter, information is transferred between the initiator module and the target module using the virtual transport session. According to another embodiment, establishing a virtual transport session between an initiator module and a target module across a network comprises associating a globally unique identifier to an initiator module.

Abstract: Database backup system identifies and extracts any changed database record using only two copies of the database from two different points in time. A first copy of the database is generated at a first time. Copies of log files including changes to the database since the first time are generated at a second time. The copy of the log files is applied to the database copy, and any changed blocks of the first copy of the database are identified. The changed blocks and a second copy of the database are used to identify changes to any record of the database between the first and second time. An archived database is generated and updated over time by archiving only data of any record that subsequently changes. Restoration of the database to a state corresponding to any point in time uses only the archived database and data of changed data records.

Abstract: Database backup system identifies and extracts any changed database record using only two copies of the database from two different points in time. A first copy of the database is generated at a first time. Copies of log files including changes to the database since the first time are generated at a second time. The copy of the log files is applied to the database copy, and any changed blocks of the first copy of the database are identified. The changed blocks and a second copy of the database are used to identify changes to any record of the database between the first and second time. An archived database is generated and updated over time by archiving only data of any record that subsequently changes. Restoration of the database to a state corresponding to any point in time uses only the archived database and data of changed data records.

Abstract: Disclosed is a method implementable by a computer system for maintaining consistency between mirrors of a mirrored data volume. In one embodiment, the method includes the computer system generating first and second write transactions in response to the generation of transaction to write data to a mirrored data volume. The first and second write transactions comprise first and second tags, respectively. The first and second tags relate the first write transaction to the second write transaction. In one embodiment, the first and second tags are identical. After the first and second write transactions are generated, the computer system transmits the first and second write transactions to first and second storage subsystems, respectively. In one embodiment, the first and second storage subsystems store or are configured to store respective mirrors of the data volume.