Abstract: Techniques are provided for replay of metadata and data operations. During initial execution of operations, identifiers of objects modified by the execution of each operation are identified and stored in association with the operations. When the operations are to be replayed (e.g., executed again, such as part of a replication operation or as part of flushing content from a cache to persistent storage), the identifiers are evaluated to determine which operations are independent with respect to one another and which operations are dependent with respect to one another. In this way, independent operations are executed in parallel and dependent operations are executed serially with respect to the operations from the dependent operations depend.

Abstract: Multi-site distributed storage systems and computer-implemented methods are described for providing an automatic unplanned failover (AUFO) feature to guarantee non-disruptive operations (e.g., operations of business enterprise applications, operations of software application) even in the presence of failures including, but not limited to, network disconnection between multiple data centers and failures of a data center or cluster.

Abstract: Systems and methods are described for performing persistent inflight tracking of operations (Ops) within a cross-site storage solution. According to one embodiment, a method comprises maintaining state information regarding a data synchronous replication status for a first storage object of a primary storage cluster and a second storage object of a secondary storage cluster. The method includes performing persistent inflight tracking of I/O operations with a first Op log of the primary storage cluster and a second Op log of the secondary storage cluster, establishing and comparing Op ranges for the first and second Op logs, and determining a relation between the Op range of the first Op log and the Op range of the second Op log to prevent divergence of Ops in the first and second Op logs and to support parallel split of the Ops.

Abstract: Techniques are provided for replay of metadata and data operations. During initial execution of operations, identifiers of objects modified by the execution of each operation are identified and stored in association with the operations. When the operations are to be replayed (e.g., executed again, such as part of a replication operation or as part of flushing content from a cache to persistent storage), the identifiers are evaluated to determine which operations are independent with respect to one another and which operations are dependent with respect to one another. In this way, independent operations are executed in parallel and dependent operations are executed serially with respect to the operations from the dependent operations depend.

Abstract: Techniques are provided for selectively allowing or blocking services from utilizing snapshots. A splitter intercepts and assigns timestamps to operations for execution upon files of a file system. If a snapshot is created while there are no pending operation, then the snapshot is tagged to indicate that the snapshot was created while there were no pending operations, and the snapshot is considered a tagged snapshot. Otherwise, the snapshot is not tagged, and is considered an untagged snapshot. Storage services (e.g., backup applications, lifecycle management applications, applications that consider timestamps of files, etc.) are allowed to utilize tagged snapshots and are blocked from utilizes untagged snapshots in order to maintain consistency.

Abstract: Techniques are provided for volume group backup, volume group restore, and volume group garbage collection for volume groups backed up to an object store. A volume group workflow is implemented to orchestrate individual consistent volume workflows that are separately and individually implemented by nodes hosting constituent volumes of a volume group. The volume group workflow and the individual consistent volume workflows are performed to back up the volume group to the object store, restore a volume group backup from the object store to a restore destination, and/or perform garbage collection on slots of objects storing data unique to a volume group backup to delete.

Abstract: Systems and methods are described for performing persistent inflight tracking of operations (Ops) within a cross-site storage solution. According to one embodiment, a method comprises maintaining state information regarding a data synchronous replication status for a first storage object of a primary storage cluster and a second storage object of a secondary storage cluster. The method includes performing persistent inflight tracking of I/O operations with a first Op log of the primary storage cluster and a second Op log of the secondary storage cluster, establishing and comparing Op ranges for the first and second Op logs, and determining a relation between the Op range of the first Op log and the Op range of the second Op log to prevent divergence of Ops in the first and second Op logs and to support parallel split of the Ops.

Abstract: Systems and methods for reducing delays between the time at which a need for a resynchronization of data replication between a volume of a local CG and its peer volume of a remote CG is detected and the time at which the resynchronization is triggered (Reseed Time Period) are provided. According to an example, information indicative of the direction of data replication between the volume and the peer volume is maintained within a cache of a node. Responsive to a disruptive operation (e.g., relocation of the volume from a first node to a second node), the Reseed Time Period is lessened by proactively adding a passive cache entry to a cache within the second node at the time the CG relationship is created when the second node represents an HA partner of the first node and prior to the volume coming online when the second node represents a non-HA partner.

Abstract: Systems and methods for reducing delays between the time at which a need for a resynchronization of data replication between a volume of a local CG and its peer volume of a remote CG is detected and the time at which the resynchronization is triggered (Reseed Time Period) are provided. According to an example, information indicative of the direction of data replication between the volume and the peer volume is maintained within a cache of a node. Responsive to a disruptive operation (e.g., relocation of the volume from a first node to a second node), the Reseed Time Period is lessened by proactively adding a passive cache entry to a cache within the second node at the time the CG relationship is created when the second node represents an HA partner of the first node and prior to the volume coming online when the second node represents a non-HA partner.

Abstract: Systems and methods are described for performing persistent inflight tracking of operations (Ops) within a cross-site storage solution. According to one embodiment, a method comprises maintaining state information regarding a data synchronous replication status for a first storage object of a primary storage cluster and a second storage object of a secondary storage cluster. The state information facilitates automatic triggering of resynchronization for data replication between the first storage object and the second storage object. The method includes performing persistent inflight tracking of I/O operations with a first Op log of the primary storage cluster and a second Op log of the secondary storage cluster, establishing and comparing Op ranges for the first and second Op logs, and determining a relation between the Op range of the first Op log and the Op range of the second Op log to prevent divergence of Ops in the first and second Op logs and to support parallel split of the Ops.

Abstract: Techniques are provided for timestamp consistency. An operation targeting a first storage object having a synchronous replication relationship with a second storage object is intercepted. A timestamp is assigned to the operation. A replication operation is created as a replication of the operation. The same timestamp is assigned to the replication operation. The operation is implemented upon the first storage object and the replication operation is implemented upon the second storage object.

Abstract: Techniques are provided for volume group backup, volume group restore, and volume group garbage collection for volume groups backed up to an object store. A volume group workflow is implemented to orchestrate individual consistent volume workflows that are separately and individually implemented by nodes hosting constituent volumes of a volume group. The volume group workflow and the individual consistent volume workflows are performed to back up the volume group to the object store, restore a volume group backup from the object store to a restore destination, and/or perform garbage collection on slots of objects storing data unique to a volume group backup to delete.

Abstract: Systems and methods for reducing delays between the time at which a need for a resynchronization of data replication between a volume of a local CG and its peer volume of a remote CG is detected and the time at which the resynchronization is triggered (Reseed Time Period) are provided. According to an example, information indicative of the direction of data replication between the volume and the peer volume is maintained within a cache of a node. Responsive to a disruptive operation (e.g., relocation of the volume from an original node to a new node), the Reseed Time Period is lessened by proactively adding a passive cache entry to a cache within the new node at the time the CG relationship is created when the new node represents an HA partner of the original node and prior to the volume coming online when the new node represents a non-HA partner.

Abstract: Systems and methods are described for performing persistent inflight tracking of operations (Ops) within a cross-site storage solution. According to one embodiment, a method comprises maintaining state information regarding a data synchronous replication status for a first storage object of a primary storage cluster and a second storage object of a secondary storage cluster. The method includes performing persistent inflight tracking of I/O operations with a first Op log of the primary storage cluster and a second Op log of the secondary storage cluster, establishing and comparing Op ranges for the first and second Op logs, and determining a relation between the Op range of the first Op log and the Op range of the second Op log to prevent divergence of Ops in the first and second Op logs and to support parallel split of the Ops.

Abstract: Systems and methods for reducing delays between the time at which a need for a resynchronization of data replication between a volume of a local CG and its peer volume of a remote CG is detected and the time at which the resynchronization is triggered (Reseed Time Period) are provided. According to an example, information indicative of the direction of data replication between the volume and the peer volume is maintained within a cache of a node. Responsive to a disruptive operation (e.g., relocation of the volume from a first node to a second node), the Reseed Time Period is lessened by proactively adding a passive cache entry to a cache within the second node at the time the CG relationship is created when the second node represents an HA partner of the first node and prior to the volume coming online when the second node represents a non-HA partner.

Abstract: Techniques are provided for persistent hole reservation. For example, hole reservation flags of operations targeting a first storage object of a first node are replicated into replication operations targeting a second storage object of a second node during a transition operation to transition the first storage object and the second storage object from an asynchronous replication state to a synchronous replication state. In another example, the second storage object is grown to a size of a replication punch hole operation that failed due to targeting a file block number greater than an end of size of the second storage object.

Abstract: Techniques are provided for volume group backup, volume group restore, and volume group garbage collection for volume groups backed up to an object store. A volume group workflow is implemented to orchestrate individual consistent volume workflows that are separately and individually implemented by nodes hosting constituent volumes of a volume group. The volume group workflow and the individual consistent volume workflows are performed to back up the volume group to the object store, restore a volume group backup from the object store to a restore destination, and/or perform garbage collection on slots of objects storing data unique to a volume group backup to delete.

Abstract: Techniques are provided for volume group backup, volume group restore, and volume group garbage collection for volume groups backed up to an object store. A volume group workflow is implemented to orchestrate individual consistent volume workflows that are separately and individually implemented by nodes hosting constituent volumes of a volume group. The volume group workflow and the individual consistent volume workflows are performed to back up the volume group to the object store, restore a volume group backup from the object store to a restore destination, and/or perform garbage collection on slots of objects storing data unique to a volume group backup to delete.

Abstract: Techniques are provided for volume group backup, volume group restore, and volume group garbage collection for volume groups backed up to an object store. A volume group workflow is implemented to orchestrate individual consistent volume workflows that are separately and individually implemented by nodes hosting constituent volumes of a volume group. The volume group workflow and the individual consistent volume workflows are performed to back up the volume group to the object store, restore a volume group backup from the object store to a restore destination, and/or perform garbage collection on slots of objects storing data unique to a volume group backup to delete.

Abstract: Techniques are provided for freeing and utilizing unused inodes. For example, an operation, targeting a first storage object of a first node having a replication relationship with a second storage object of a second node, is intercepted. A replication operation is created as a replication of the operation. The operation is implemented upon the first storage object and the replication operation is implemented upon the second storage object. A determination is made that the replication operation uses an inode no longer used by storage objects of the second node. The inode targeted by the replication operation is freed and utilized based upon the inode being a leaf inode. If the inode is a stream directory inode, then data streams of the stream directory inode are moved under a new private inode and the stream directory inode is released.