Abstract: A technique improves storage efficiency of an object store configured to maintain numerous snapshots for long-term storage in an archival storage system by efficiently determining data that is exclusively owned by an expiring snapshot to allow deletion of the expiring snapshot from the object store. The technique involves managing index data structures to enable efficient garbage collection across a very large number of data objects. When a snapshot expires, the technique obviates the need to scan the numerous snapshot data objects to determine which index structures are no longer needed and can be reclaimed (garbage collected). The technique is directed to management of underlying storage based on different sets of policies. When certain snapshots expire and are ready for deletion, the technique is directed to finding those data blocks that are no longer referenced (used) by any valid snapshots.

Abstract: A reference snapshot selection technique is configured to select a reference snapshot resolution algorithm used to determine an appropriate reference snapshot that may be employed to perform incremental snapshot replication of workload data between primary and secondary sites in a data replication environment. A reference resolution procedure is configured to process a set of constraints from the data replication environment to dynamically select the reference snapshot resolution algorithm based on a figure of merit that satisfies administrative constraints to reduce or optimize resource utilization in the data replication environment.

Abstract: A technique improves storage efficiency of an object store configured to maintain numerous snapshots for long-term storage in an archival storage system by efficiently determining data that is exclusively owned by an expiring snapshot to allow deletion of the expiring snapshot from the object store. The technique involves managing index data structures to enable efficient garbage collection across a very large number of data objects. When a snapshot expires, the technique obviates the need to scan the numerous snapshot data objects to determine which index structures are no longer needed and can be reclaimed (garbage collected). The technique is directed to management of underlying storage based on different sets of policies. When certain snapshots expire and are ready for deletion, the technique is directed to finding those data blocks that are no longer referenced (used) by any valid snapshots.

Abstract: A reference snapshot selection technique is configured to select a reference snapshot resolution algorithm used to determine an appropriate reference snapshot that may be employed to perform incremental snapshot replication of workload data between primary and secondary sites in a data replication environment. A reference resolution procedure is configured to process a set of constraints from the data replication environment to dynamically select the reference snapshot resolution algorithm based on a figure of merit that satisfies administrative constraints to reduce or optimize resource utilization in the data replication environment.

Abstract: An indexing technique provides an index data structure for efficient retrieval of a snapshot from a long-term storage service (LTSS) of an archival storage system. The snapshot is generated from typed data of a logical entity, such as a virtual disk (vdisk). The data of the snapshot is replicated to a frontend data service of the LTSS sequentially and organized as one or more data objects for storage by a backend data service of LTSS in an object store of the archival storage system. Metadata associated with the snapshot (i.e., snapshot metadata) is recorded as a log and persistently stored on storage media local to the frontend data service. The snapshot metadata includes information describing the snapshot data, e.g., a logical offset range of a snapshot of the vdisk and, thus, is used to construct the index data structure. Notably, construction of the index data structure is deferred until after the entirety of the snapshot data has been replicated and received by the frontend data service.

Abstract: Methods, systems and computer program products for high-availability computing. In a computing configuration comprising a primary node, a first backup node, and a second backup node, a particular data state is restored to the primary node from a backup snapshot at the second backup node. Firstly, a snapshot coverage gap is identified between a primary node snapshot at the primary node and the backup snapshot at the second backup node. Next, intervening snapshots at the first backup node that fills the snapshot coverage gap are identified and located. Having both the backup snapshot from the second backup node and the intervening snapshots from the first backup node, the particular data state at the primary node is restored by performing differencing operations between the primary node snapshot, the backup snapshot from the second backup node, and the intervening snapshots of the first backup node.

Abstract: A system and method determining a Chain Identification Number (CID) of a source snapshot to be replicated from a source site to a target site of a virtual computing system, determining a predetermined number of potential reference snapshots based on the CID of the source snapshot, computing a closeness value between the source snapshot and each of the potential reference snapshots, and creating a list of the potential reference snapshots based on the closeness value of each of the potential reference snapshots. One snapshot from the list is selected as a reference snapshot. The source snapshot is replicated to the target site based on the reference snapshot.

Abstract: A system and method determining a Chain Identification Number (CID) of a source snapshot to be replicated from a source site to a target site of a virtual computing system, determining a predetermined number of potential reference snapshots based on the CID of the source snapshot, computing a closeness value between the source snapshot and each of the potential reference snapshots, and creating a list of the potential reference snapshots based on the closeness value of each of the potential reference snapshots. One snapshot from the list is selected as a reference snapshot. The source snapshot is replicated to the target site based on the reference snapshot.

Abstract: Methods, systems and computer program products for high-availability computing. In a computing configuration comprising a primary node, a first backup node, and a second backup node, a particular data state is restored to the primary node from a backup snapshot at the second backup node. Firstly, a snapshot coverage gap is identified between a primary node snapshot at the primary node and the backup snapshot at the second backup node. Next, intervening snapshots at the first backup node that fills the snapshot coverage gap are identified and located. Having both the backup snapshot from the second backup node and the intervening snapshots from the first backup node, the particular data state at the primary node is restored by performing differencing operations between the primary node snapshot, the backup snapshot from the second backup node, and the intervening snapshots of the first backup node.