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, and an incrementing token.

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: A method in one embodiment for operating a virtual server supporting at least one Write Once Read Many (WORM) logical data object and at least one read-write logical object includes initializing a logical data object from a common pool of the logical data objects, the logical data object bound with a member of a media type group, the member of the media type group comprising a WORM logical data object and a read-write logical data object; and reusing one of the logical data objects as the member of the media type group without ejection and reinsertion by mounting the logical data object with a write from beginning of logical data object to bind at least one data attribute to the member of the media type group to replace any previous attribute and data associated with the logical data object.

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: For selecting an input/output tape volume cache (TVC), a history module maintains access history instances for a plurality of clusters, each cluster comprising a TVC. A request module receives an access request for a logical volume wherein an instance of the logical volume is stored on each of the plurality of clusters and each instance of the logical volume is synchronized with each other instance of the logical volume. An adjustment module weights the access history instances in favor of recent access history instances. A calculation module calculates an affinity of the logical volume instance stored on each cluster of the plurality of clusters. A selection module selects a cluster TVC with a highest logical volume affinity as the TVC for the logical volume.

Abstract: An apparatus, system, and method are disclosed for selecting an input/output tape volume cache (TVC). A history module maintains access history instances for a plurality of clusters. A request module receives an access request for a logical volume. An adjustment module weights the access history instances in favor of recent access history instances. A calculation module calculates an affinity of the logical volume for each cluster of the plurality of clusters. The calculation module may calculate the affinity of the logical volume for each cluster of the plurality of clusters using read/write/scratch granularity and an algorithm. Further, the calculation module may filter out clusters. A selection module selects a cluster TVC with a highest affinity as the TVC for the logical volume.

Abstract: Various method, system, and computer program product embodiments for implementing selective write-protect by a processor in a data storage system within a plurality of redundant storage systems for disaster recovery testing are provided. In one such embodiment, a write-protect state is initiated within at least one of the plurality of redundant storage systems. An available plurality of categories, including at least one write-protect exclusion category, is configured within a management interface of the data storage system, such that during the disaster recovery testing a storage volume categorized in the write-protect exclusion category is excluded from write protection.

Abstract: A composite storage server employs a plurality of distributed storage sites including a mount site, a source copy site and one ore more copy target sites for executing a storage of volume data within the composite storage server. In operation, a deferred copy target site receives a communication of a source copy complete message from the mount site, the source copy complete message being indicative of the source copy site having a complete copy of the volume data, and detects a transition by the mount site of the host job from an active status to an inactive status subsequent to the communication of the source copy complete message from the mount site. Based on the inactive status of the host job, the deferred copy target site pulls the volume data from a peer distributed storage site having a complete copy of the volume data.

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: An embodiment of the invention comprises a virtual tape system supporting at least one Write Once Read Many (WORM) logical tape and at least one read-write logical tape, comprising a processor configured to a first task and/or a second task. The first task initializes a new logical data object from a single pool of at least two logical data objects, with the new logical data object bound with a member of a media type group consisting of a WORM data object or a read-write data object. The second task reuses one of the logical data objects without manual ejection and reinsertion. The reuse may include the processor configured to cycle the logical data object through a scratch pool as a selected scratch logical data object and mount the selected scratch logical data object with a write from beginning of tape command to bind at least one data attribute to the WORM data object.

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: Various method, system, and computer program product embodiments for selective device access control in a data storage system are provided. In one such embodiment, a plurality of access groups associated with logical devices used to access the data storage system is initialized. Each of the plurality of access groups corresponds to a range of the logical devices. An access group name of one of the access groups is bound to a logical volume of the data storage system at a volume creation. The logical volume, once bound to the access group name, is granted access by those of the logical devices in a range of the logical devices corresponding to the one of the access groups.

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: 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: Various method, system, and computer program product embodiments for implementing selective write-protect by a processor in a data storage system within a plurality of redundant storage systems for disaster recovery testing are provided. In one such embodiment, a write-protect state is initiated within at least one of the plurality of redundant storage systems. An available plurality of categories, including at least one write-protect exclusion category, is configured within a management interface of the data storage system, such that during the disaster recovery testing a storage volume categorized in the write-protect exclusion category is excluded from write protection.

Abstract: A composite storage server employs a plurality of distributed storage sites including a mount site, a source copy site and one or more copy target sites for executing a storage of volume data within the composite storage server. In operation, an immediate copy target site receives a communication of a source copy complete message from the mount site, the source copy complete message being indicative of the source copy site having a complete copy of the volume data. Based on the source copy complete message, the immediate copy target site pulls the volume data from a peer distributed storage site having a complete copy of the volume data (e.g., the source copy site, the mount site or another copy target site).

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: A method for throttling host throughput in a computer storage subsystem is provided. The host throughput is compared to a throughput limit for a predetermined time period. If the host throughput exceeds the throughput limit during the predetermined time period, an input/output (I/O) delay is set equal to the remainder of the predetermined time period, and the delay is implemented for an associated storage device of the computer storage subsystem.

Abstract: A method for controlling the throughput in a communications channel between a host and its storage subsystem is disclosed. A determination is made whether or not a total throughput value is greater than a predetermined maximum throughput value. If the total throughput value is greater than the predetermined maximum throughput value, a delay is applied to the communications channel. If the total throughput value is not greater than the predetermined maximum throughput value, another determination is made whether or not one time period has completed. If one time period has completed, a total throughput value and an exponential moving average (EMA) throughput value of the communications channel is retrieved, a new EMA throughput value is generated based on the total throughput value and the EMA throughput value, and adjusting the total throughput value based on whether or not the new throughput value is greater than a predetermined maximum throughput value.