Abstract: Cluster families for cluster selection and cooperative replication are created. 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. Each family member in the family replicates 1/Nth volumes and N represents a total number of cluster family members in the family.

Abstract: Provided are a computer program product, system, and method for synchronous mode replication to multiple clusters receiving a write to a volume from a host. A received write is cached in a memory. A determination is made of a replication rule indicating one of a plurality of replication modes for a first cluster and a second cluster used for replication for the write, wherein one of the replication modes comprises a synchronous mode. A determination is made that the replication rule indicates a synchronous mode for the first and the second clusters. The write is transmitted from the memory to the first cluster to store in a first non-volatile storage of the first cluster and to the second cluster to store in a second non-volatile storage in response to determining that the replication rule indicates the synchronous mode.

Abstract: A method according to one embodiment includes copying data incoming to and/or generated at a production site to a copy cluster at a remote copy site, thereby creating a redundant copy of the data at the copy cluster. When the copy cluster becomes unavailable, data incoming to and/or generated at the production site is copied to a backup reserve site after the copy cluster becomes unavailable. Additional systems, methods, and computer programs products are also presented.

Abstract: A method according to one embodiment includes selecting, by a processor, one of a WORM logical data object and a read-write logical data object for reuse as a new WORM logical data object, said processor maintaining data attributes bound to said selected logical data object until it is determined that said selected logical data object is available for reuse. At least one temporary data attribute is assigned to said selected logical data object while maintaining said data attributes bound to said selected logical data object The selected logical data object is mounted and a write command to beginning of logical data object is received to bind at least one data attribute to said selected logical data object to replace data attributes and data associated with said selected logical data object to reuse said selected logical data object as said new WORM logical data object.

Abstract: In one embodiment, a system includes a processor and logic integrated with and/or executable by the processor, the logic being configured to cause the processor to define a disaster recovery (DR) family, the DR family having one or more DR clusters accessible to a DR host and one or more production clusters accessible to a production host, wherein the DR host is configured to replicate data from the one or more production clusters to the one or more DR clusters, create a backup copy of data stored to the one or more production clusters, store the backup copy to the one or more DR clusters, establish a time-zero in the DR family, and share a point-in-time data consistency at the time-zero among all clusters within the DR family. Other systems, methods, and computer program products are presented for DR testing, according to more embodiments.

Abstract: In one embodiment, a system includes a processor and logic integrated with and/or executable by the processor, the logic being configured to cause the processor to access a snapshot of data stored on one or more DR clusters within a disaster recovery (DR) family only when the snapshot was made consistent with respect to data on one or more production clusters within the DR family before a time-zero, and perform DR testing using the snapshot, wherein the time-zero represents a time selected to simulate a disaster, wherein the DR family includes one or more DR clusters accessible to a DR host and the one or more production clusters accessible to a production host, and wherein the DR host is configured to replicate data from the one or more production clusters to the one or more DR clusters.

Abstract: In one embodiment, an apparatus includes a processor and logic integrated with and/or executable by the processor configured to cause the processor to receive data to store to a first cluster, store one or more copies of the data to the first cluster, and set a time-delayed copy consistency point time-delayed cops consistency point indicating an amount of time in which data stored to the first cluster is aged prior to being copied from the first cluster to a second cluster. In another embodiment, a method for time-delayed replication includes receiving data to store to a first cluster, storing one or more copies of the data to the first cluster, and setting a time-delayed copy consistency point, the time-delayed copy consistency point indicating an amount of time in which data stored to the first cluster is aged prior to being copied from the first cluster to a second cluster.

Abstract: A method according to one embodiment includes selecting, by a processor, one of a WORM logical data object and a read-write logical data object for reuse as a new WORM logical data object, said processor maintaining data attributes bound to said selected logical data object until it is determined that said selected logical data object is available for reuse. At least one temporary data attribute is assigned to said selected logical data object while maintaining said data attributes bound to said selected logical data object The selected logical data object is mounted and a write command to beginning of logical data object is received to bind at least one data attribute to said selected logical data object to replace data attributes and data associated with said selected logical data object to reuse said selected logical data object as said new WORM logical data object.

Abstract: An apparatus, system, and method are disclosed for maintaining a context stack. A monitor module monitors a stack size after each monitor interval for a stack of a plurality of contexts. Each context defines communications between a process and a data set and comprises a pathway for communicating with the data set and a process identifier. A stack module deallocates a context that satisfies a stack policy from the stack if the stack size is within a buffer threshold of a maximum threshold.

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: An apparatus, system, and method are disclosed for maintaining a context stack. A monitor module monitors a stack size after each monitor interval for a stack of a plurality of contexts. Each context defines communications between a process and a data set and comprises a pathway for communicating with the data set and a process identifier. A stack module deallocates a context that satisfies a stack policy from the stack if the stack size is within a buffer threshold of a maximum threshold.

Abstract: Cluster families for cluster selection and cooperative replication are created. 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. Each family member in the family replicates 1/Nth volumes and N represents a total number of cluster family members in the family.

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: 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: Provided are a computer program product, system, and method for synchronous mode replication to multiple clusters receiving a write to a volume from a host. A received write is cached in a memory. A determination is made of a replication rule indicating one of a plurality of replication modes for a first cluster and a second cluster used for replication for the write, wherein one of the replication modes comprises a synchronous mode. A determination is made that the replication rule indicates a synchronous mode for the first and the second clusters. The write is transmitted from the memory to the first cluster to store in a first non-volatile storage of the first cluster and to the second cluster to store in a second non-volatile storage in response to determining that the replication rule indicates the synchronous mode.

Abstract: Methods, systems, and computer program products for selective device access control in a data storage system are provided. A method includes initializing a plurality of access groups associated with logical devices used to access the data storage system, each of the plurality of access groups corresponding to a range of the logical devices, pursuant to a mount of a logical volume of the data storage system, and binding an access group name of one the plurality of access groups to at least one of a metadata of the logical volume at a volume creation and a volume header of the logical volume, wherein 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 plurality of 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, 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: Methods, systems, and computer program products for selective device access control in a data storage system are provided. A method includes initializing a plurality of access groups associated with logical devices used to access the data storage system, each of the plurality of access groups corresponding to a range of the logical devices, pursuant to a mount of a logical volume of the data storage system, and binding an access group name of one the plurality of access groups to at least one of a metadata of the logical volume at a volume creation and a volume header of the logical volume, wherein 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 plurality of access groups.

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.