Abstract: Synchronizing metadata among storage systems synchronously replicating a dataset, where synchronizing the metadata includes: receiving, at a first storage system of the storage systems, an I/O operation directed to the dataset; determining, in dependence upon the I/O operation, a metadata update describing a mapping of segments of content to a virtual address within a storage object, wherein the storage object includes the dataset; and synchronizing metadata on a second storage system of the storage systems by sending the metadata update to the second storage system to update a metadata representation on the second storage system in accordance with the metadata update.

Abstract: Performing a non-disruptive upgrade of data in a storage system that includes a plurality of storage devices and a storage controller, including: creating new data in a new data format, wherein the new data includes a reference to old data in an old data format, wherein system software in the storage system can utilize data in the new data format and the old data format; determining that a portion of the volume has changed; and responsive to determining that the portion of the volume has changed, updating the new data to include a reference to old data associated with a portion of the volume that precedes the changed portion of the volume, new data associated with the changed portion of the volume, and a reference to old data associated with a portion of the volume that follows the changed portion of the volume.

Abstract: Determining active membership among a set of storage systems synchronously replicating a dataset, where determining active membership includes: determining that a membership event corresponds to a change in membership to the set of storage systems synchronously replicating the dataset; applying, in dependence upon the membership event, one or more membership protocols to determine a new set of storage systems to synchronously replicate the dataset; and for one or more I/O operations directed to the dataset, applying the one or more I/O operations to the dataset synchronously replicated by the new set of storage systems.

Abstract: Managing connectivity to synchronously replicated storage systems, including: identifying a plurality of storage systems across which a dataset is synchronously replicated; identifying a host that can issue I/O operations directed to the dataset; identifying a plurality of data communications paths between the host and the plurality of storage systems across which a dataset is synchronously replicated; identifying, from amongst the plurality of data communications paths between the host and the plurality of storage systems across which a dataset is synchronously replicated, one or more optimal paths; and issuing, to the host, an identification of the one or more optimal paths.

Abstract: The described embodiments are directed to a system and methods of calibrating a fluorescence microscope and/or light detection device using a calibrating apparatus. The apparatus may comprise a main body housing, a sensor head, and a microcontroller assembly disposed within the housing. The housing may include an adapter to mechanically couple the housing to a microscope. The sensor head may comprise (i) an optical power sensor to produce a power signal representative of an optical power magnitude of light applied to the optical power sensor, (ii) an optical wavelength sensor configured to produce wavelength information associated with the light applied to the optical wavelength sensor, and (iii) a light source configured to direct light toward a detection device associated with the microscope. The microcontroller assembly may be configured to generate an optical power magnitude value based on the power signal and adjusted according to the wavelength information.

Abstract: Automatic storage system configuration for mediation services that includes: determining that a particular storage system of the storage systems is not configured to request mediation from a mediation target for mediation between storage systems synchronously replicating a dataset; requesting, by the particular storage system from a configuration service, configuration information indicating one or more service handles for a mediation service; and configuring, in dependence upon the one or more service handles received from the configuration service, a mediation handler to communicate with the mediation service responsive to detecting a communication fault with one of the storage systems.

Abstract: Embodiments are directed to determining active membership among a set of storage systems synchronously replicating a dataset. Determining active membership among a set of storage systems synchronously replicating a dataset includes determining that a membership event corresponds to a change in membership to the set of storage systems synchronously replicating the dataset. Determining active membership further includes applying, in dependence upon the membership event, one or more membership protocols to determine a new set of storage systems to synchronously replicate the dataset. Determining active membership also includes, for one or more I/O operations directed to the dataset, applying the one or more I/O operations to the dataset synchronously replicated by the new set of storage systems.

Abstract: Determining active membership among storage systems synchronously replicating a dataset, where determining active membership includes: detecting, by a particular storage system of the storage systems, a communication fault with one or more of the storage systems, where the particular storage system is configured to request mediation from a mediation target; determining that at least one of the one or more storage systems is configured to request mediation from the mediation target responsive to the communication fault; and responsive to determining that one or more of the storage systems is configured to request mediation from the mediation target, determining whether to request mediation from the mediation target.

Abstract: Mediating between storage systems synchronously replicating a dataset, including: requesting, by a first storage system in response to detecting a triggering event, a lock for a shared resource from a mediation service; requesting, by a second storage system in response to detecting the triggering event, the lock for the shared resource from the mediation service; and responsive to acquiring the lock from the mediation service, the first storage system, instead of the second storage system, processing data storage requests directed to the dataset that is synchronously replicated across the first storage system and the second storage system.

Abstract: Servicing I/O operations directed to a dataset that is synchronized across a plurality of storage systems, including: receiving, by a follower storage system, a request to modify the dataset; sending, from the follower storage system to a leader storage system, a logical description of the modification to the dataset; receiving, from the leader storage system, information describing the modification to the dataset; processing, by the follower storage system, the request to modify the dataset; receiving, from the leader storage system, an indication that the leader storage system has processed the request to modify the dataset; and acknowledging, by the follower storage system, completion of the request to modify the dataset.

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: A storage system asynchronously replicating a synchronously replicated dataset, where the asynchronous replication of the asynchronously replicated dataset includes: determining, at a target storage system, multiple work items corresponding to a dataset stored among multiple source storage systems, wherein each respective work item corresponds to a respective subset of the dataset; and for each session from among a plurality of sessions operating on the target storage system: determining one or more computing environment factors affecting performance of replication of data from one or more of the multiple source storage systems to the target storage system; identifying, for a given session and based on the one or more computing environment factors, a respective source storage system and a quantity of work items; and replicating, from the respective storage system, one or more subsets of data corresponding to the quantity of work items.

Abstract: A storage system switching mediators within a storage system synchronously replicating data, where the switching between mediators includes: determining, among one or more of the plurality of storage systems, a change in availability of a first mediator service, wherein one or more of the plurality of storage systems are configured to request mediation from the first mediator service; communicating, among the plurality of storage systems and responsive to determining the change in availability of the first mediator service, a second mediator service to use in response to a fault; and switching, in dependence upon the change in availability of the first mediator service, from the first mediator service to the second mediator service.

Abstract: A storage system switching between mediation models within a storage system, where the switching between mediation models includes: determining, among one or more of the plurality of storage systems, a change in availability of a mediator service, wherein one or more of the plurality of storage systems are configured to request mediation from the mediator service in response to a fault; and communicating, among the plurality of storage systems and responsive to determining the change in availability of the mediator service, a fault response model to be used as an alternate to the mediator service among one or more of the plurality of storage systems.

Abstract: Systems, methods, and computer readable storage mediums for optimizing performance in a storage system. A volume may be mapped to an anchor medium through an indirection layer. When a snapshot is taken of the volume, the allocation of a new anchor medium is delayed until a write operation targeting the volume is received. When a write operation targeting the volume is received, a new anchor medium may be allocated for only a portion of the volume corresponding to the portion of the volume which is targeted by the write operation. Also, when a snapshot is taken of the volume, read optimization operations are performed only the portions of the volume which have changed since the previous snapshot.

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: Establishing a synchronous replication relationship between two or more storage systems, including: identifying, for a dataset, a plurality of storage systems across which the dataset will be synchronously replicated; configuring one or more data communications links between each of the plurality of storage systems to be used for synchronously replicating the dataset; exchanging, between the plurality of storage systems, timing information for at least one of the plurality of storage systems; and establishing, in dependence upon the timing information for at least one of the plurality of storage systems, a synchronous replication lease, the synchronous replication lease identifying a period of time during which the synchronous replication relationship is valid.

Abstract: A system and method for exposing volumes with underlying read-write mediums to user operations. When a medium is in the process of being replicated to a storage array, a volume which relies on the medium can be exposed to user operations (e.g., snapshots, read and write operations) once the portions of the medium which underlie the volume have been replicated. The volume can be exposed to user operations while one or more other portions of the medium are unfilled and while the medium is in an intermediate read-write state.

Abstract: Optimizing copy operations in a storage array, including: receiving a plurality of copy operations; detecting a triggering event that causes a storage array controller to initiate execution of the plurality of copy operations; and combining, in dependence upon a metadata optimization policy, the plurality of copy operations into a single copy operation.

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.