Abstract: A disaster recovery storage array automatically generates snapshots of replica storage objects responsive to detection of interruption of asynchronous replication of production storage objects of a primary storage system to the replica storage objects. The primary storage array accumulates updates to the production storage objects over a plurality of asynchronous replication cycles during the interruption. Asynchronous replication automatically resumes when the interruption ends. Accumulation of updates and resumption of asynchronous replication may be performed iteratively if there are multiple interruptions before the replica storage objects are consistent with the production storage objects. The snapshots are automatically discarded after the replica storage objects are made consistent with the production storage objects.

Abstract: A disaster recovery storage array automatically generates snapshots of replica storage objects responsive to detection of interruption of asynchronous replication of production storage objects of a primary storage system to the replica storage objects. The primary storage array accumulates updates to the production storage objects over a plurality of asynchronous replication cycles during the interruption. Asynchronous replication automatically resumes when the interruption ends. Accumulation of updates and resumption of asynchronous replication may be performed iteratively if there are multiple interruptions before the replica storage objects are consistent with the production storage objects. The snapshots are automatically discarded after the replica storage objects are made consistent with the production storage objects.

Abstract: Unmap extents transmitted in delta sets are used to unmap LBAs on remote replicas of asynchronously replicated storage objects. A host server sends a SCSI unmap command to a production storage array to unmap a range of logical block addresses. In response, the production storage array creates an unmap extent that identifies the local and remote replicas, starting LBA, and number of LBAs to be unmapped. At the end of each asynchronous replication cycle, unmap extents and updated data are sent to a disaster recovery storage array in a delta set that preserves chronological ordering. The disaster recovery storage array receives the delta set and discards cached data corresponding to the unmapped LBAs indicated in the unmap extents and de-allocates the backend storage space. Integrating unmap extents with updated data in delta sets maintains point-in-time consistency and is more efficient than sending zero data.

Abstract: An apparatus in one embodiment includes at least one processing device comprising a processor coupled to a memory. The at least one processing device is configured to obtain, in a host device, inter-system response time information based at least in part on one or more response times measured by at least one of first and second storage systems relative to another one of the first and second storage systems, and to automatically control, based at least in part on the obtained inter-system response time information, active-standby designations for respective ones of the first and second storage systems. For example, in some embodiments, automatically controlling active-standby designations for respective ones of the first and second storage systems illustratively comprises controlling activation of an active-standby mode of operation based at least in part on comparison of at least a portion of the inter-system response time information to one or more specified thresholds.

Abstract: Unmap extents transmitted in delta sets are used to unmap LBAs on remote replicas of asynchronously replicated storage objects. A host server sends a SCSI unmap command to a production storage array to unmap a range of logical block addresses. In response, the production storage array creates an unmap extent that identifies the local and remote replicas, starting LBA, and number of LBAs to be unmapped. At the end of each asynchronous replication cycle, unmap extents and updated data are sent to a disaster recovery storage array in a delta set that preserves chronological ordering. The disaster recovery storage array receives the delta set and discards cached data corresponding to the unmapped LBAs indicated in the unmap extents and de-allocates the backend storage space. Integrating unmap extents with updated data in delta sets maintains point-in-time consistency and is more efficient than sending zero data.

Abstract: Snapshots may be used to implement remote replication, for example, asynchronously, between a first storage system, A1, and a second storage system, A2. A1 may take a first snapshot, SS21, of a logical storage unit, R1. After the snapshot SS21 it taken, any dependent write operations associated with SS21 may be reconciled, and differences between SS21 and the last snapshot for R1, SS11, may be determined and recorded as a difference set. One or more replication instructions for R1 that include the write operations (or data and metadata corresponding thereto) of the difference set may be sent from A1 to A2. A2 may apply the differences to R2, and then take (activate) a snapshot of R2, SS22, which is a replica of SS21. After A2 activates SS22, A2 may send an acknowledgement to A1 indicating that SS22 has been activated, and A2 may take a next snapshot of R1.

Abstract: Data may be replicated from a host storage system to a target storage system. It may be determined to replicate a first logical storage element on the source storage system to a second logical storage element on the target storage system, wherein the first logical storage element defines a first data portion having a first value. It may be determined that a third logical storage element on the target storage system defines a second data portion having the first value. The first logical storage element may be replicated to the second logical storage element by establishing a deduplication relationship between the second logical storage element and the third logical storage element on the target storage system without transmitting the first data portion from the source storage system to the target storage system.

Abstract: Aspects of the present disclosure relate to data cache management. In embodiments, a logical block address (LBA) bucket is established with at least one logical LBA group. Additionally, at least one LBA group is associated with two or more distinctly sized cache slots based on an input/output (IO) workload received by the storage array. Further, the association includes binding the two or more distinctly sized cache slots with at least one LBA group and mapping the bound distinctly sized cache slots in a searchable data structure. Furthermore, the searchable data structure identifies relationships between slot pointers and key metadata.

Abstract: A device and method for operating a lighting system varies a characteristic of visible light emitted by a first lighthead according to a predefined profile, and fixes a characteristic of visible light emitted by a second lighthead. A light sensor configured to view a focal area of the second lighthead detects a characteristic of visible light on a target surface over a period of time, and the characteristic of the light detected by the light sensor over the period of time is compared to the characteristic of light defined in the predetermined profile. A mode of operation of the first and second lighthead is determined based on the comparison.

Abstract: A device and method for operating a lighting system varies a characteristic of visible light emitted by a first lighthead according to a predefined profile, and fixes a characteristic of visible light emitted by a second lighthead. A light sensor configured to view a focal area of the second lighthead detects a characteristic of visible light on a target surface over a period of time, and the characteristic of the light detected by the light sensor over the period of time is compared to the characteristic of light defined in the predetermined profile. A mode of operation of the first and second lighthead is determined based on the comparison.

Abstract: Data may be replicated from a host storage system to a target storage system. It may be determined to replicate a first logical storage element on the source storage system to a second logical storage element on the target storage system, wherein the first logical storage element defines a first data portion having a first value. It may be determined that a third logical storage element on the target storage system defines a second data portion having the first value. The first logical storage element may be replicated to the second logical storage element by establishing a deduplication relationship between the second logical storage element and the third logical storage element on the target storage system without transmitting the first data portion from the source storage system to the target storage system.

Abstract: Aspects of the present disclosure relate to data cache management. In embodiments, a storage array's memory is provisioned with cache memory, wherein the cache memory includes one or more sets of distinctly sized cache slots. Additionally, a logical storage volume (LSV) is established with at least one logical block address (LBA) group. Further, at least one of the LSV's LBA groups is associated with two or more distinctly sized cache slots based on an input/output (IO) workload received by the storage array.

Abstract: Cache slots on a storage system may be shared between entities processing write operations for logical storage unit (LSU) tracks and entities performing remote replication for write operations for the LSU tracks. If a new write operation is received on a first storage system (S1) for a track of an LSU (R1) when the cache slot mapped to the R1 track is locked by a process currently transmitting data of the cache slot to a second storage system (S2), a new cache slot may be allocated to the R1 track, the data of the original cache slot copied to the new cache slot, and the new write operation for the R1 track initiated on S1 using the new cache slot; while the data of the original cache slot is independently, and perhaps concurrently, transmitted to S2 to be replicated in R2, the LSU on S2 that is paired with R1.

Abstract: Aspects of the present disclosure relate to data cache management. In embodiments, a storage array's memory is provisioned with cache memory, wherein the cache memory includes one or more sets of distinctly sized cache slots. Additionally, a logical storage volume (LSV) is established with at least one logical block address (LBA) group. Further, at least one of the LSV's LBA groups is associated with two or more distinctly sized cache slots based on an input/output (IO) workload received by the storage array.

Abstract: Aspects of the present disclosure relate to data cache management. In embodiments, a logical block address (LBA) bucket is established with at least one logical LBA group. Additionally, at least one LBA group is associated with two or more distinctly sized cache slots based on an input/output (IO) workload received by the storage array. Further, the association includes binding the two or more distinctly sized cache slots with at least one LBA group and mapping the bound distinctly sized cache slots in a searchable data structure. Furthermore, the searchable data structure identifies relationships between slot pointers and key metadata.

Abstract: Data may be replicated from a host storage system to a target storage system. It may be determined to replicate a first logical storage element on the source storage system to a second logical storage element on the target storage system, wherein the first logical storage element defines a first data portion having a first value. It may be determined that a third logical storage element on the target storage system defines a second data portion having the first value. The first logical storage element may be replicated to the second logical storage element by establishing a deduplication relationship between the second logical storage element and the third logical storage element on the target storage system without transmitting the first data portion from the source storage system to the target storage system.

Abstract: Snapshots may be used to implement remote replication, for example, asynchronously, between a first storage system, A1, and a second storage system, A2. A1 may take a first snapshot, SS21, of a logical storage unit, R1. After the snapshot SS21 it taken, any dependent write operations associated with SS21 may be reconciled, and differences between SS21 and the last snapshot for R1, SS11, may be determined and recorded as a difference set. One or more replication instructions for R1 that include the write operations (or data and metadata corresponding thereto) of the difference set may be sent from A1 to A2. A2 may apply the differences to R2, and then take (activate) a snapshot of R2, SS22, which is a replica of SS21. After A2 activates SS22, A2 may send an acknowledgement to A1 indicating that SS22 has been activated, and A2 may take a next snapshot of R1.

Abstract: Maintaining consistency for asynchronous replication of LUNs of a local storage system to corresponding LUNs of a remote storage system includes copying application data written to LUNs to cache slots, copying metadata of LUNs to cache slots, associating a first sequence number to all metadata modifications and all application data writes that are begun after a first time and before a second time, associating a second sequence number, different from the first sequence number, to all metadata modifications and all application data writes that are begun after the second time, and, after completion of all metadata modifications and all application data writes associated with the first sequence number, initiating transfer to the remote storage system of all metadata modifications and all application data writes associated with the first sequence number. Each cache slot may include a field that indicates a corresponding sequence number.

Abstract: Peer storage systems share the workload of asynchronously replicating a shared logical storage unit (LSU) to a target system. Peer storage systems (S1 and S2) that synchronously replicate a shared LSU share the workload of asynchronously replicating the shared LSU to a target system (S3) by dividing ownership of the replication cycles in an alternating manner without a strict synchronization of cycles between the peer storage systems. Rather, a given cycle number (e.g., Cycle 1) on S1 may not start and end with a same write operation as a same cycle number (Cycle 1) on S2, such that cycles on S1 (e.g., Cycle 1 and Cycle 2) overlap with cycles having the same number (Cycle 1 and Cycle 2) on S2. S1 may asynchronously replicate to S3 only the cycles it owns, and S2 may asynchronously replicate to S3 only the cycles it owns to S3.

Abstract: Cache slots on a storage system may be shared between entities processing write operations for logical storage unit (LSU) tracks and entities performing remote replication for write operations for the LSU tracks. If a new write operation is received on a first storage system (S1) for a track of an LSU (R1) when the cache slot mapped to the R1 track is locked by a process currently transmitting data of the cache slot to a second storage system (S2), a new cache slot may be allocated to the R1 track, the data of the original cache slot copied to the new cache slot, and the new write operation for the R1 track initiated on S1 using the new cache slot; while the data of the original cache slot is independently, and perhaps concurrently, transmitted to S2 to be replicated in R2, the LSU on S2 that is paired with R1.