Abstract: In one aspect, a method of testing a device for use in a storage area network (SAN) system includes receiving recorded messages including messages from a host and from a storage array and messages to a host and to a storage array, sending the recorded messages from the host and the storage array to a device under test, receiving messages from the device under test in response to the recorded messages sent and determining whether the device under test functions identically to a validated device based on the messages from the device under test being substantially identical to the recorded messages.

Abstract: An apparatus and method for information recovery quality assessment in a computing environment is disclosed. This includes a group of inter-related software modules and associated data structures that analyze and assess the recoverability of the network data through the data protection configuration setup and a previously performed data protection process. It examines in a comprehensive manner the recoverability perspective across a pre-defined data protection domain, such as a computer network with an organization. The results of the examination provide for the display of inconsistencies of data protection configuration and previously performed data protection processes that consequently result in problems of recovering the network objects in an appropriate manner.

Abstract: In one aspect, a method to replicate data includes determining if an I/O data block from a journal is generated by a replication initialization process; if the I/O data block from a journal is generated by the replication initialization process, determining if the I/O data block from the journal comprises zero data; if the I/O data block from the journal comprises the zero data, reading an I/O data block in a volume; and determining if the I/O data block from the volume comprises zero data. The method also includes, if the I/O data block from the volume comprises zero data, bypassing writing the I/O data block from the journal to the I/O data block in the volume.

Abstract: In one aspect, a method of consolidating snapshots includes storing snapshots using a journal in a continuous data protection environment. Each entry of the journal corresponds to one of a unique group of DO METADATA stream data blocks and a unique group of UNDO METADATA stream data blocks. The method also includes receiving a user input designating at least two snapshots to consolidate, storing changes to the data blocks from the at least two snapshots in a temporary stream on the journal and consolidating the at least two snapshots by replacing the at least two snapshots in the journal with a single consolidated snapshot comprising the changes for each data block from the temporary stream. Storing changes includes storing one of the oldest changes of the UNDO METADATA stream data blocks and the latest changes of the DO METADATA stream data blocks.

Abstract: In one aspect, a method to perform initialization prior to replication includes marking a first point in a delta marking stream, generating a copy of a local volume at the first point and determining dirty locations between a remote volume and the copy. The copy is generated from one of taking a snapshot or taking a clone of the local volume.

Abstract: In one aspect, a method to convert a logical unit from a first encryption state to a second encryption state includes receiving a request to convert a logical unit from a first encryption state to a second encryption state, partitioning the logical unit into areas comprising a converted area, an unconverted area and a transition area, writing unconverted data in the transition area to a journal, converting the unconverted data from the first encryption state to the second encryption state and writing the converted data to the logical unit.

Abstract: Method and apparatus for detecting viruses in a continuous data protection system using by scanning journal data. In an exemplary embodiment, a system stores journal data, receiving a virus signature update containing a first new virus signature, scanning the journal data for the first new virus signature, and identifying a data block containing the first new virus signature for a first virus.

Abstract: In one aspect, a method to perform synchronization in a network-based system includes notifying a source side appliance that I/O data is going to be written to a source side storage and a target side appliance, waiting for an acknowledgement that the notification was received and writing I/O data to the source side storage and the target side appliance.

Abstract: In one aspect, a method to recover data includes annotating metadata entries in a journal to indicate changes by an application to an object stored in a continuous data protection environment. Each entry of the metadata corresponds to one of a unique group of DO stream data blocks or a unique group of UNDO stream data blocks. The method also includes determining a version of the object that meets criteria by searching the annotated entries and obtaining the version of the object that meets the criteria. In another aspect, a method to recover data includes receiving criteria to recover an object, determining a version of the object that meets the criteria by searching point-in-time images using a DO stream and an UNDO stream and obtaining the version of the object that meets the criteria.

Abstract: Method and apparatus to provide bottleneck processing in a continuous data protection system having journaling. In an exemplary embodiment, system parameter information is collected and analyzed to output bottleneck information.

Abstract: In one aspect, a method of dynamically adding a new node includes determining if the new node is included in a list of nodes belonging to a network cluster, notifying the leader node if the new node is not included in the list, adding the new node to the list and notifying the new node that it is a member of the network cluster. In another aspect, a method of dynamically removing a node includes determining if the node is functioning and if not, removing the node from a list of nodes belonging to a network cluster. In a further aspect, a method of dynamically managing a network cluster includes determining if a twin of a node is malfunctioning, removing the twin from a twin state of the node, removing the twin from a leader candidate list and adding a new node to the leader candidate list.

Abstract: Method and apparatus to dynamically add storage for a journal in a continuous data protection system. In an exemplary embodiment, a method includes storing a plurality of journal data streams for a journal in a continuous data protection system in first storage, where streams in the journal data streams contain linked lists of data blocks, determining when the first storage exceeds a selected fullness threshold, allocating second storage for the journal in addition to the first storage, and storing data for the journal in the second storage.

Abstract: Method and apparatus to compress journal data in a continuous data protection system. An exemplary embodiment includes storing journal data including a do data stream and an undo data stream in a continuous data protection system, compressing data prior to entry in the do data stream, storing compression information in a do metadata stream for the do data stream entry, accessing the data for the entry in the do data stream, examining the do metadata stream for the entry, and decompressing the do data stream entry and writing the decompressed data to storage.

Abstract: A method and apparatus for winding an elongate member, such as a strip or wire, under tension around a body comprising a frame maintained at a preset distance from the body and movable around the body by means including a belt held against rotation relative to the body and two belt engaging members each selectively adapted to be clamped against and released from the belt. One of the belt engaging members is fixed relative to the frame and the other of the members is movable relative to the frame in a first direction when the one member is engaged with the belt and in the opposite direction when the other member is engaged with the belt to move the frame relative to the body. The frame carries a guide for guiding the elongate member onto the body and a mechanism for tensioning the strip as it is wound on the body.

Abstract: A conduit for conveyance of hot fluids includes an inner tube, through which the fluid passes, made of a material having a low coefficient of thermal expansion, preferably less than 5 .times. 10.sup.-6 per .degree. C and advantageously INVAR .RTM. with a coefficient of 2.3 .times. 10.sup.-6 /.degree. C. The inner tube is anchored at its ends and has no expansion-compensating means in its length is surrounded by a binding wrapping of a material having a coefficient of thermal expansion greater than that of the inner tube, prestressed at the temperature of application to compensate for the relaxation of stress in the wrapping due to the different expansions of inner tube and wrapping, and so as to compensate at least in part for changes in stress on the inner tube resulting from the absence of expansion-compensating means. A longitudinal tensile pre-stress may also be applied. The assembly also includes thermal insulation, disposed either outside the wrapping or between the wrapping and the inner tube.

Abstract: In rock drilling utilizing mechanical destruction of the rock and circulation of drilling fluid for removing debris from the cutting face, the drilling fluid is directed on to the cutting face in the form of two opposed pulsed jets, the cycles of which are 180.degree. out of phase. In order to achieve the phased opposition of the pulsed jets a ball is disposed in the distribution chamber of the drilling fluid and is subjected to a combination of hydraulic and mechanical forces which cause the ball to oscillate between two end positions in which the ball respectively closes off one of two outlet ducts leading to nozzles which direct the drilling fluid towards opposite points on the bottom of the drill hole.

Abstract: Apparatus for winding at least one strip of an elongate product, such as a wire or ribbon, on to a cylindrical body from a spool of the product comprising means for producing relative rotation of the spool around the cylindrical body, a main drive unit for driving the rotation producing apparatus and connected to the axle of the spool through a differential driven by a secondary drive unit for braking the spool to tension said product. The secondary drive unit may be controlled by the output of a tension sensing mechanism sensing the tension of the product.