Abstract: Provided are a method, system, and article of manufacture for maintaining message versions at nodes in a network. The nodes in the network maintain version information of nodes in the network. The version information for the nodes indicates a message version number of messages supported at the node. The nodes supporting one message version number can receive messages having that message version number. The nodes use the version information to determine whether there is at least one common message version number among the nodes The nodes supporting the at least one common message version number negotiate to join a quorum of the nodes having the at least one common message version number.

Abstract: An apparatus, system, and method are disclosed to create cluster families for cluster selection and cooperative replication. The clusters are grouped into family members of a cluster family base on their relationships and roles. Members of the cluster family determine which family member is in the best position to obtain replicated information and become cumulatively consistent within their cluster family. Once the cluster family becomes cumulatively consistent, the data is shared within the cluster family so that all copies within the cluster family are consistent.

Abstract: An apparatus, system, and method are disclosed for link maintenance. A plurality of state machines operate a plurality of first links between data management nodes with each first link in an online state. A transition module transitions the plurality of first links from the online state to a degraded state and from the online state to an offline pending state in response to an offline request. The transition module further transitions the plurality of first links from the degraded state to an online pending state when a degraded link time interval expires and from the offline pending state to an offline state if all pending tasks on the plurality of first links are completed. The transition module further transitions the plurality of first links from the online pending state to the online state if each first link is validated.

Abstract: A data storage system stores logical data object(s), each identified by a logical identifier. A control is configured to assign a unique WORM (Write Once Read Many) identifier to the logical data object, and stores the unique WORM identifier as associated with the logical identifier, in a database maintained by the control so as to be persistent. Data storage is configured to write the logical data object with a header with the unique WORM identifier. The control, in order to allow the logical data object to be accessed externally to the control, requires matching the unique WORM identifier in the header of a logical data object to the unique WORM identifier of the persistent database for the logical object. The unique WORM identifier is formed of a checksum hash value related to nonce fields comprising at least the logical identifier of the logical data object, and an incrementing token.

Abstract: An apparatus, system, and method are disclosed for cooperative replication of multiple clusters. A copy request to copy a volume into a first cluster is received. A determination is made whether the first cluster is a family member of a cluster family. If the first cluster is a family member of the cluster family, a determination is made whether another family member already completed copying the volume. If another family member has not already copied the volume, the first cluster is designated to inherit the copy request. The copy request is executed and the volume is cooperative replicated into the cluster family. Cumulative consistency is achieved within the cluster family. The volume is shared within the cluster family so that all copies of the volume within the cluster family are consistent.

Abstract: A method for offloading volume space reclamation operations to virtual tape systems is disclosed herein. In certain embodiments, such a method includes writing instruction information to a virtual tape system for use in performing a reclamation operation on a source virtual tape volume. The instruction information identifies the source virtual tape volume as well as valid objects in the source virtual tape volume. The virtual tape system then transforms the source virtual tape volume by retaining valid objects in the source virtual tape volume, removing invalid objects in the source virtual tape volume, and updating metadata associated with the source virtual tape volume to reflect changes made thereto. This generates an updated source virtual tape volume of reduced size. A corresponding computer program product and system are also disclosed and claimed herein.

Abstract: An apparatus, system, and method are disclosed for cooperative replication of multiple clusters. A copy request to copy a volume into a first cluster is received. A determination is made whether the first cluster is a family member of a cluster family. If the first cluster is a family member of the cluster family, a determination is made whether another family member already completed copying the volume. If another family member has not already copied the volume, the first cluster is designated to inherit the copy request. The copy request is executed and the volume is cooperative replicated into the cluster family. Cumulative consistency is achieved within the cluster family. The volume is shared within the cluster family so that all copies of the volume within the cluster family are consistent.

Abstract: A data storage system stores logical data object(s), each identified by a logical identifier. A control is configured to assign a unique WORM (Write Once Read Many) identifier to the logical data object, and stores the unique WORM identifier as associated with the logical identifier, in a database maintained by the control so as to be persistent. Data storage is configured to write the logical data object with a header with the unique WORM identifier. The control, in order to allow the logical data object to be accessed externally to the control, requires matching the unique WORM identifier in the header of a logical data object to the unique WORM identifier of the persistent database for the logical object. The unique WORM identifier is formed of a checksum hash value related to nonce fields comprising at least the logical identifier of the logical data object, an incrementing token, and a time stamp.

Abstract: Link information for a plurality of links to at least one target node indicates for each link a send throughput for sending data, a receive throughput for received data, a slate of the link indicating whether the link is online, offline or degraded. The send throughput of the links having the online state is processed to select one of the links to the receiving node m response to determining that more than one of the links has the online state. The data of the send operation is sent using the selected link to the receiving node. The receive throughput is processed to select one of the links having the online state to the sending node in response to determining that more than one of the links has the online state. The data of the receive operation is received using the selected link to the sending node.

Abstract: A hybrid data storage system is one which has data storage clusters of different types. In a hybrid data storage system, at least one first data storage cluster is configured to store data and has high data storage capacity; and at least one second data storage cluster is configured to store data and has lower data storage capacity than the first cluster. The data is initially replicated and stored by at least one first and at least one second data storage cluster. The method identifies a portion of the stored initially replicated data of at least one second data storage cluster as “pinned”; continues to store the pinned initially replicated data; and selectively removes non-pinned initially replicated data from the second data storage cluster(s) to account for the capacity difference.

Abstract: Local versions of attributes of a storage object are maintained at a plurality of nodes, wherein a first attribute designates a first node of the plurality of nodes as an owner node for the storage object, and wherein a second attribute includes information to resolve validity of ownership of the storage object among the plurality of nodes. The owner node communicates changes to be made to the local versions of the attributes at other nodes of the plurality of nodes. A second node of the plurality of nodes requests ownership of the storage object. The first attribute is updated to designate the second node of the plurality of nodes as the owner node, in response to determining from the second attribute that the validity of ownership of the storage object allows the second node to inherit ownership of the storage object once the first node surrenders ownership of the storage object.

Abstract: Provided are a method, system, and article of manufacture, wherein a storage manager application implemented in a first computational device maintains a virtual logical volume that represents a plurality of segments of a linear storage medium of a secondary storage, wherein the virtual logical volume and the plurality of segments are created by the storage manager application. A request for data is received at the first computational device, from a second computational device. The storage manager application moves selected segments of the plurality of segments from the linear storage medium of the secondary storage to a cache storage, in anticipation that the requested data is included in the selected segments that are moved from the linear storage medium of the secondary storage to the cache storage.

Abstract: An apparatus, system, and method are disclosed to create cluster families for cluster selection and cooperative replication. The clusters are grouped into family members of a cluster family base on their relationships and roles. Members of the cluster family determine which family member is in the best position to obtain replicated information and become cumulatively consistent within their cluster family. Once the cluster family becomes cumulatively consistent, the data is shared within the cluster family so that all copies within the cluster family are consistent.

Abstract: Provided are a method, system, and article of manufacture, wherein a plurality of nodes coupled over a network are maintained, wherein a first node of the plurality of nodes initially owns a plurality of storage objects accessible via the network. A second node preemptively takes ownership of a selected storage object of the plurality of storage objects, in response to the first node becoming unavailable, wherein other nodes of the plurality of nodes can request ownership of the selected storage object while the first node is unavailable. A determination is made that the first node that originally owned the selected storage object has become available after a period of unavailability. A determination is made of the current owner node of the selected storage object, wherein the current owner node is one of the second node and the other nodes.

Abstract: Provided are a method, system, and article of manufacture that maintain a plurality of nodes coupled over a network, wherein a first node of the plurality of nodes initially owns a plurality of storage objects accessible via the network. A serialization lock is maintained in association with the plurality of storage objects, wherein the first node becomes unavailable. A second node of the plurality of nodes determines that the second node is to preemptively assume ownership of a selected storage object of the plurality of storage objects initially owned by the first node that has become unavailable. The second node acquires the serialization lock. The second node secures ownership of the selected storage object, subsequent to acquiring the serialization lock.

Abstract: An apparatus, system, and method are disclosed for link maintenance. A plurality of state machines operate a plurality of first links between data management nodes with each first link in an online state. A transition module transitions the plurality of first links from the online state to a degraded state and from the online state to an offline pending state in response to an offline request. The transition module further transitions the plurality of first links from the degraded state to an online pending state when a degraded link time interval expires and from the offline pending state to an offline state if all pending tasks on the plurality of first links are completed. The transition module further transitions the plurality of first links from the online pending state to the online state if each first link is validated.

Abstract: Provided are a method, system, and article of manufacture for using link send and receive information to select one of multiple links to use to transfer data for send and receive operations. Link information for a plurality of links to at least one target node indicates for each link a send throughput for sending data, a receive throughput for received data, a state of the link indicating whether the link is online, offline or degraded. A send operation is processed to transfer data to a receiving node comprising one of the target nodes. A determination is made of the states of the links to the receiving node in response to the send operation. The send throughput of the links having the online state is processed to select one of the links to the receiving node in response to determining that more than one of the links has the online state. The data of the send operation is sent using the selected link to the receiving node.

Abstract: In a system including an application subsystem node having an application RSID table and a logging subsystem node having a logging RSID table, the application subsystem node makes a determination of a registration status of a ALSI string relative to the application RSID table during a logging operation of the ALSI string. The application subsystem node further transfers a RSID package from the application subsystem node across a network to the logging subsystem node, wherein the RSID package includes a RSID encoding of the ALSI string and conditionally includes the ALSI string based on the registration status of the ALIS string relative to the application RSID table as determined by the application subsystem node.

Abstract: Provided are a method, system, and article of manufacture, wherein a plurality of nodes coupled over a network are maintained, wherein a first node of the plurality of nodes initially owns a plurality of storage objects accessible via the network. A second node preemptively takes ownership of a selected storage object of the plurality of storage objects, in response to the first node becoming unavailable, wherein other nodes of the plurality of nodes can request ownership of the selected storage object while the first node is unavailable. A determination is made that the first node that originally owned the selected storage object has become available after a period of unavailability. A determination is made of the current owner node of the selected storage object, wherein the current owner node is one of the second node and the other nodes.

Abstract: Provided are a method, system, and article of manufacture for maintaining message versions at nodes in a network. The nodes in the network maintain version information of nodes in the network. The version information for the nodes indicates a message version number of messages supported at the node. The nodes supporting one message version number can receive messages having that message version number. The nodes use the version information to determine whether there is at least one common message version number among the nodes The nodes supporting the at least one common message version number negotiate to join a quorum of the nodes having the at least one common message version number.