Abstract: A system and method for performing replication using mediums. A snapshot ‘S’ is selected for replication, and the anchor medium ‘M’ of S is identified. The replica storage array ‘R’ to which M is being replicated determines a list of medium extents which are available. R sends this list to an original storage array ‘O’ and O generates a list of medium extents which need to be sent to R. Only those medium extents corresponding to M which R does not already have will be sent from O to R. Also, R can obtain medium extents from other source storage arrays during the replication process.

Abstract: A method of mapping equivalent hosts at distinct replication endpoints, the method including: receiving an indication that a first host mapped to a source dataset at a replication source is equivalent to a second host for a replica dataset at a replication target of the source dataset; transmitting, from the replication source to the replication target and based on an update to the source dataset received from the first host, metadata describing the update to the source dataset; and mapping, based on the indication that the first host mapped to the source dataset at the replication source is equivalent to the second host for the replica dataset at the replication target, the second host to the replica dataset at the replication target of the source dataset.

Abstract: A method of managing host mappings for replication endpoints, the method including: identifying a target storage system replicating a source dataset of a source storage system, wherein a first host is mapped to the source dataset on the source storage system; providing, to the target storage system and in dependence upon a mapping of the first host to the source dataset, configuration information for connecting to a second host; and implementing, in response to a triggering event, a mapping of the second host to a replica dataset on the target storage system.

Abstract: A pod, the pod including the dataset, a set of managed objects and management operations, a set of access operations to modify or read the dataset, and a plurality of storage systems, where: management operations can modify or query managed objects equivalently through any of the storage systems, access operations to read or modify the dataset operate equivalently through any of the storage systems, each storage system stores a separate copy of the dataset as a proper subset of the datasets stored and advertised for use by the storage system, and operations to modify managed objects or the dataset performed and completed through any one storage system are reflected in subsequent management objects to query the pod or subsequent access operations to read the dataset.

Abstract: Distributing management responsibilities for a storage system that includes a storage array controller and a plurality of storage devices, including: identifying a plurality of elements in the storage system; for each of the plurality of elements in the storage system, creating a distributed manager, wherein each distributed manager is configured for gathering information describing the state of the associated element in the storage system, determining an action to perform against the associated element in the storage system, and executing an approved action against the associated element in the storage system; and creating a distributed management hierarchy that includes each of the distributed managers.

Abstract: Ensuring crash-safe forward progress of a system configuration update in a storage system that includes a storage array controller and a plurality of storage devices, including: determining a number of storage devices in the storage system; determining a number of unavailable storage devices in the storage system; and determining, for the one or more system configurations, whether the system configuration can be reconstructed in dependence upon the number of storage devices in the storage system and the number of unavailable storage devices in the storage system.

Abstract: An add-on lens assembly supporting an add-on lens for a camera includes a locking mechanism actuatable by the user in order to increase the attachment force between the lens and the camera. The add-on lens assembly may include a rotatable lock ring having a cam pin that navigates along a surface of a cam such that when the lock ring is rotated, the cam pin causes the cam to translate axially. Axial translation of the cam may compress a spring within the assembly and increase the attachment force between the lens assembly and the camera. The increased force between the add-on lens assembly and the camera may provide additional support for large or heavy assemblies.

Abstract: A system and method for performing replication using mediums. A snapshot ‘S’ is selected for replication, and the anchor medium ‘M’ of S is identified. The replica storage array ‘R’ to which M is being replicated determines a list of medium extents which are available. R sends this list to an original storage array ‘O’ and O generates a list of medium extents which need to be sent to R. Only those medium extents corresponding to M which R does not already have will be sent from O to R. Also, R can obtain medium extents from other source storage arrays during the replication process.

Abstract: A pod, the pod including the dataset, a set of managed objects and management operations, a set of access operations to modify or read the dataset, and a plurality of storage systems, where: management operations can modify or query managed objects equivalently through any of the storage systems, access operations to read or modify the dataset operate equivalently through any of the storage systems, each storage system stores a separate copy of the dataset as a proper subset of the datasets stored and advertised for use by the storage system, and operations to modify managed objects or the dataset performed and completed through any one storage system are reflected in subsequent management objects to query the pod or subsequent access operations to read the dataset.

Abstract: Managing host definitions across a plurality of storage systems, including: creating, on a first storage system, a host definition describing a host that accesses a dataset that is replicated across a plurality of storage systems; determining whether a second storage system that the dataset is replicated across includes a definition of the host; responsive to determining that the second storage system does not include a definition of the host, copying the host definition created on the first storage system to the second storage system; responsive to determining that the second storage system does include a definition of the host: linking the host definition created on the first storage system to the definition of the host on the second storage system or retaining the definition of the host on the second storage system.

Abstract: Distributing management responsibilities for a storage system that includes a storage array controller and a plurality of storage devices, including: identifying a plurality of elements in the storage system; for each of the plurality of elements in the storage system, creating a distributed manager, wherein each distributed manager is configured for gathering information describing the state of the associated element in the storage system, determining an action to perform against the associated element in the storage system, and executing an approved action against the associated element in the storage system; and creating a distributed management hierarchy that includes each of the distributed managers.

Abstract: Ensuring crash-safe forward progress of a system configuration update in a storage system that includes a storage array controller and a plurality of storage devices, including: determining a number of storage devices in the storage system; determining a number of unavailable storage devices in the storage system; and determining, for the one or more system configurations, whether the system configuration can be reconstructed in dependence upon the number of storage devices in the storage system and the number of unavailable storage devices in the storage system.

Abstract: Systems, apparatuses, methods, and computer-readable storage mediums for performing lease-based fencing using a time-limited lease window. During the time-limited lease window, writes to a shared storage medium are permitted, while writes are denied for expired leases. When a successful heartbeat is generated for a primary storage controller, the lease window is extended for the primary storage controller from the time of a previous heartbeat. Accordingly, a prolonged stall between successive heartbeats by the primary storage controller will result in the newly extended lease being expired at the time it is granted. This scheme prevents a split brain scenario from occurring when a secondary storage controller takes over as the new primary storage controller in response to detecting the stall.

Abstract: Systems, apparatuses, methods, and computer-readable storage mediums for performing lease-based fencing using a time-limited lease window. During the time-limited lease window, writes to a shared storage medium are permitted, while writes are denied for expired leases. When a successful heartbeat is generated for a primary storage controller, the lease window is extended for the primary storage controller from the time of a previous heartbeat. Accordingly, a prolonged stall between successive heartbeats by the primary storage controller will result in the newly extended lease being expired at the time it is granted. This scheme prevents a split brain scenario from occurring when a secondary storage controller takes over as the new primary storage controller in response to detecting the stall.

Abstract: An add-on lens assembly supporting an add-on lens for a camera includes a locking mechanism actuatable by the user in order to increase the attachment force between the lens and the camera. The add-on lens assembly may include a rotatable lock ring having a cam pin that navigates along a surface of a cam such that when the lock ring is rotated, the cam pin causes the cam to translate axially. Axial translation of the cam may compress a spring within the assembly and increase the attachment force between the lens assembly and the camera. The increased force between the add-on lens assembly and the camera may provide additional support for large or heavy assemblies.

Abstract: A pod, the pod including the dataset, a set of managed objects and management operations, a set of access operations to modify or read the dataset, and a plurality of storage systems, where: management operations can modify or query managed objects equivalently through any of the storage systems, access operations to read or modify the dataset operate equivalently through any of the storage systems, each storage system stores a separate copy of the dataset as a proper subset of the datasets stored and advertised for use by the storage system, and operations to modify managed objects or the dataset performed and completed through any one storage system are reflected in subsequent management objects to query the pod or subsequent access operations to read the dataset.

Abstract: An add-on lens assembly supporting an add-on lens for a camera includes a locking mechanism actuatable by the user in order to increase the attachment force between the lens and the camera. The add-on lens assembly may include a rotatable lock ring having a cam pin that navigates along a surface of a cam such that when the lock ring is rotated, the cam pin causes the cam to translate axially. Axial translation of the cam may compress a spring within the assembly and increase the attachment force between the lens assembly and the camera. The increased force between the add-on lens assembly and the camera may provide additional support for large or heavy assemblies.

Abstract: Ensuring crash-safe forward progress of a system configuration update in a storage system that includes a storage array controller and a plurality of storage devices, including: determining a number of storage devices in the storage system; determining a number of unavailable storage devices in the storage system; and determining, for the one or more system configurations, whether the system configuration can be reconstructed in dependence upon the number of storage devices in the storage system and the number of unavailable storage devices in the storage system.

Abstract: Distributing management responsibilities for a storage system that includes a storage array controller and a plurality of storage devices, including: identifying a plurality of elements in the storage system; for each of the plurality of elements in the storage system, creating a distributed manager, wherein each distributed manager is configured for gathering information describing the state of the associated element in the storage system, determining an action to perform against the associated element in the storage system, and executing an approved action against the associated element in the storage system; and creating a distributed management hierarchy that includes each of the distributed managers.

Abstract: An add-on lens assembly supporting an add-on lens for a camera includes a locking mechanism actuatable by the user in order to increase the attachment force between the lens and the camera. The add-on lens assembly may include a rotatable lock ring having a cam pin that navigates along a surface of a cam such that when the lock ring is rotated, the cam pin causes the cam to translate axially. Axial translation of the cam may compress a spring within the assembly and increase the attachment force between the lens assembly and the camera. The increased force between the add-on lens assembly and the camera may provide additional support for large or heavy assemblies.