Abstract: An illustrative unified data storage method includes providing, by a data storage system, block containers that represent a linear address space of blocks; and using, by the data storage system, the block containers to store content for a plurality of different data storage services. In certain examples, the different data storage services include at least one of a file storage service, an object storage service, or a database service.

Abstract: Modifying a clone image of a dataset, including: generating, based on metadata describing one or more updates to a dataset, a tracking copy of replica data on a target data repository; generating, after receiving an indication to begin accepting modifications to the tracking copy of the replica data, a cloned image of the dataset that is modifiable without modifying the tracking copy of the replica data; and responsive to a storage operation directed to the target data repository, modifying the cloned image of the dataset without modifying the tracking copy of the replica data.

Abstract: Managing storage systems that are synchronously replicating a dataset, including: detecting a change in membership to the set of storage systems synchronously replicating the dataset; and applying one or more membership protocols to determine a new set of storage systems to synchronously replicate the dataset, wherein the one or more membership protocols include a quorum protocol, an external management protocol, or a racing protocol, and wherein one or more I/O operations directed to the dataset are applied to a new set of storage systems.

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: Prioritizing highly performant storage systems for servicing a synchronously replicated dataset: detecting a communication fault between two or more storage systems that are synchronously replicating a dataset; identifying a preferred storage system for winning mediation, including determining that the preferred storage system winning mediation would result in better performance than other storage systems winning mediation; and requesting, by the preferred storage system, mediation from a mediation target.

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: Resilient mediation between storage systems replicating a dataset, including: receiving, by a mediation service from one or more storage systems that synchronously replicate a dataset, a request to resolve which storage system continues to service a dataset after the request; and sending, from the mediation service to at least one of the storage systems, a positive mediation result, wherein: the storage systems that received the positive mediation result continue to process data storage requests directed to the dataset, and the storage systems that did not receive a positive mediation result from the mediation service do not continue to process data storage requests directed to the dataset.

Abstract: A uniform model for distinct types of data replication, including receiving, at a source data repository, an update to a dataset; generating, based on the update to the dataset, both metadata describing the update to the dataset and also a metadata representation of the dataset; and initiating, based on the same metadata describing the update to the dataset and also based on the same metadata representation of the dataset, either a first type of data replication or a second type of data replication from among a plurality of types of data replication.

Abstract: Transitioning between replication sources for data replication operations, including: delaying a transition from using a first data repository as a source for data replication to using a second data repository as the source for data replication after detecting that one or more storage operations directed to the first data repository have not been replicated to the second data repository; and promoting the second data repository as the source for data replication such that storage operations received after completing the transition are directed to the second data repository.

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: A system and method for exposing volumes with underlying read-write mediums to user operations. When a medium is in the process of being migrated 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 migrated. 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: Maintaining a synchronous replication relationship between two or more storage systems, including: receiving, by at least one of a plurality of storage systems across which a dataset will be synchronously replicated, timing information for at least one of the plurality of storage systems; and establishing, based on the timing information, a synchronous replication lease describing a period of time during which the synchronous replication relationship is valid, wherein a request to modify the dataset may only be acknowledged after a copy of the dataset has been modified on each of the storage systems.

Abstract: Generating datasets using approximate baselines including receiving, by a source storage system, an instruction to create, on a target storage system, a current snapshot for a source dataset stored on the source storage system, wherein no snapshots for the source dataset exist on the target storage system; selecting, as a baseline dataset, a similar dataset from a plurality of datasets on the source storage system with an existing snapshot on the target storage system, wherein the similar dataset comprises at least a portion of the source dataset; instructing the target storage system to generate a baseline snapshot for the source dataset using a copy of the existing snapshot of the baseline dataset; and transferring, from the source storage system to the target storage system, only a difference between the baseline dataset and the source dataset.

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: Initiating recovery actions when a dataset ceases to be synchronously replicated across a set of storage systems, including: receiving, by at least one storage system among a plurality of storage systems implementing a symmetric input/output model for a synchronously replicated dataset, a request to modify the dataset; identifying one or more operations associated with the request to modify the dataset that have not been applied to at least one storage system of the plurality of storage systems; and responsive to a system fault among the plurality of storage systems synchronously replicating the dataset, applying a recovery action based on recovery information that identifies one or more operations that have not been applied to the plurality of storage systems.

Abstract: Prioritizing highly performant storage systems for servicing a synchronously replicated dataset: detecting a communication fault between two or more storage systems that are synchronously replicating a dataset; identifying a preferred storage system for winning mediation, including determining that the preferred storage system winning mediation would result in better performance than other storage systems winning mediation; and requesting, by the preferred storage system, mediation from a mediation target.

Abstract: Optimizing copy operations in a storage array, includes combining, in dependence upon a metadata optimization policy, a plurality of copy operations into a single copy operation and splitting the single copy operation into an optimized set of executable copy operations that copy data based on memory alignment.

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: Modifying a clone image of a dataset, including: generating, based on metadata describing one or more updates to a dataset, a tracking copy of replica data on a target data repository; generating, after receiving an indication to begin accepting modifications to the tracking copy of the replica data, a cloned image of the dataset that is modifiable without modifying the tracking copy of the replica data; and responsive to a storage operation directed to the target data repository, modifying the cloned image of the dataset without modifying the tracking copy of the replica data.

Abstract: Managing storage systems that are synchronously replicating a dataset, including: detecting a change in membership to the set of storage systems synchronously replicating the dataset; and applying one or more membership protocols to determine a new set of storage systems to synchronously replicate the dataset, wherein the one or more membership protocols include a quorum protocol, an external management protocol, or a racing protocol, and wherein one or more I/O operations directed to the dataset are applied to a new set of storage systems.