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: Recovery in a cloud-based storage system, including: receiving, by the cloud-based storage system among a plurality of storage systems synchronously replicating a dataset, a request to modify the dataset; generating recovery information indicating whether the request to modify the dataset has been applied on all storage systems in the plurality of storage systems synchronously replicating the dataset; and responsive to a system fault, applying a recovery action in dependence upon the recovery information indicating whether the request to modify the dataset has been applied on all storage systems in the plurality of storage systems synchronously replicating the dataset.

Abstract: Staging data in a cloud-based storage system, including: receiving, by a storage controller application executing on cloud computing resources in a cloud-based storage system, a data storage operation from a computer device, wherein the cloud-based storage system includes a first tier of cloud storage and a second tier of cloud storage; storing data corresponding to the data storage operation within the first tier of cloud storage provided using a first cloud storage service; and responsive to detecting a condition for transferring data between the first tier of cloud storage and the second tier of cloud storage, transferring the data in the first tier of cloud storage to a second tier of cloud storage provided using a second cloud storage service, wherein the first cloud storage service is different than the second cloud storage service.

Abstract: Intelligently compressing data in a storage array that includes a plurality of storage devices, including: prioritizing, in dependence upon an expected benefit to be gained from compressing each data element, one or more data elements; receiving an amount of processing resources available for compressing the one or more of the data elements; and selecting, in dependence upon the prioritization of the one or more data elements and the amount of processing resources available for compressing one or more of the data elements, a data compression algorithm to utilize on one or more of the data elements.

Abstract: A storage system determines a present amount of reclaimable space in storage memory. The storage system determines a garbage collection directive based on the present amount of reclaimable space in comparison to a target amount of reclaimable space. The storage system selects blocks of storage memory for a group of blocks for garbage collection. Each block selected has greater than or equal to a threshold amount of reclaimable space in accordance with the garbage collection directive. The storage system performs garbage collection, using blocks from the group.

Abstract: Staging data in a cloud-based storage system, including: receiving, at the cloud-based storage system integrating a first tier of cloud storage and a second tier of cloud storage, a data storage operation from a computer device; storing data corresponding to the data storage operation within the first tier of cloud storage in accordance with a first storage format; and responsive to detecting a condition for transferring data between the first tier of cloud storage and the second tier of cloud storage, transferring the data in the first storage format from the first tier of cloud storage to a second data format within the second tier of cloud storage.

Abstract: Leveraging distinct storage tiers in a virtual storage system, including: receiving a request to write data to the virtual storage system; selecting, from amongst a plurality of tiers in the virtual storage system, a tier for receiving the data, wherein the plurality of tiers include a write-mostly tier and at least one other tier; and storing, within the selected tier within the virtual storage system, the data.

Abstract: Synchronously replicating a dataset across cloud-based storage systems, including adding a cloud-based storage system to a set of storage systems that the dataset is synchronously replicated across, where access operations are applied to the dataset equivalently through all storage systems in the set, all storage systems in the set store a separate copy of the dataset, and operations to modify the dataset performed and completed through any of the storage systems in the set are reflected in access operations to read the dataset, the cloud-based storage system including one or more cloud computing instances executing a storage controller application, a virtual drive layer that includes one or more cloud computing instances with local storage for storing at least a portion of the dataset as block data, and an object storage layer for storing at least a portion of the dataset as object data.

Abstract: Servicing I/O operations in a virtual storage system, including: receiving, by the virtual storage system, a request to write data to the virtual storage system; storing, within staging memory provided by one or more virtual drives of the virtual storage system, the data; and migrating, from the staging memory to more durable data storage provided by a cloud services provider, at least a portion of data stored within the staging memory.

Abstract: Servicing I/O operations in a virtual storage system, including: receiving, by the virtual storage system, a request to write data to the virtual storage system; storing, within staging memory provided by one or more virtual drives of the virtual storage system, both the data and an erasure code based on the data; and migrating, from the staging memory to more durable data storage provided by a cloud services provider, at least a portion of data stored within the staging memory without migrating the erasure code based on the data.

Abstract: A storage system for synchronously replicating a dataset across hardware-based storage systems and cloud-based storage systems, the storage system including specifying a set of managed objects, a set of management operations, and a set of access operations to correspond to the dataset, where management operations can modify or query managed objects equivalently through the hardware-based storage systems and the cloud-based storage systems; access operations to read or modify the dataset operate equivalently through the hardware-based storage systems and the cloud-based storage systems; each hardware-based storage system and each cloud-based storage system stores a separate copy of the dataset as a proper subset of the datasets stored and advertised for use; and operations to modify managed objects or the dataset performed and completed through the hardware-based storage systems and the cloud-based storage systems are reflected in subsequent management objects to query the dataset or subsequent access operatio

Abstract: A cloud-based storage system contained in a cloud computing environment, the cloud-based storage system including: determining, at the cloud-based storage system and in response to a request for data, that the data previously stored within one or more virtual instances of a virtual instance layer is no longer stored within the one or more virtual instances; generating, within the virtual instance layer, a quantity of virtual instances to receive data restored from a cloud-based storage layer of the cloud-based storage system; and restoring, into the quantity of virtual instances at the virtual instance layer, data from the cloud-based storage layer of the cloud-based storage system.

Abstract: Servicing I/O operations in a cloud-based storage system, including: receiving, by the cloud-based storage system, a request to write data to the cloud-based storage system; storing, in solid-state storage of the cloud-based storage system, the data; storing, in object storage of the cloud-based storage system, the data; detecting that at least some portion of the solid-state storage of the cloud-based storage system has become unavailable; identifying data that was stored in the portion of the solid-state storage of the cloud-based storage system that has become unavailable; retrieving, from object storage of the cloud-based storage system, the data that was stored in the portion of the solid-state storage of the cloud-based storage system that has become unavailable; and storing, in solid-state storage of the cloud-based storage system, the retrieved data.

Abstract: Symmetric storage using a cloud-based storage system, including: receiving, at a cloud-based storage system among storage systems synchronously replicating a dataset, 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 an address within a storage object, wherein the storage object includes the dataset; and synchronizing metadata on another storage system of the storage systems by sending the metadata update from the cloud-based storage system to the other storage system to update a metadata representation on the second storage system in accordance with the metadata update.

Abstract: Determining active membership among a set of storage systems, including: determining, by a cloud-based storage system among the set of storage systems, 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: Servicing I/O operations in a virtual storage system, including: receiving, by the virtual storage system, a request to write data to the virtual storage system; storing, within staging memory provided by one or more virtual drives of the virtual storage system, the data; and migrating, from the staging memory to more durable data storage provided by a cloud services provider, at least a portion of data stored within the staging memory.

Abstract: Efficiently transferring data between tiers in a virtual storage system, including: receiving, by the virtual storage system, a request to write data to the virtual storage system; transforming, within storage provided by a first tier of storage of the virtual storage system, the data to generate transformed data; and migrating, from the first tier of storage to a second tier of storage that is more durable than the first tier of storage of the virtual storage system, at least a portion of the transformed data.

Abstract: Data recovery in a virtual storage system, including: detecting, within storage provided by a first tier of storage of the virtual storage system, data loss within a dataset, wherein recovery data for the dataset is stored in a second tier of storage; determining a recovery point for the dataset up to which a consistent version of the dataset is recoverable from the recovery data stored in the second tier of storage; and restoring, within the storage provided by the first tier of storage of the virtual storage system, the consistent version of the dataset.

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: A storage system performs garbage collection with data compression. A storage controller in the storage system determines a garbage collection directive by evaluating the amount of reclaimable space relative to a target amount of reclaimable space. Garbage collection is performed using data compression tunable to compression aggressiveness according to the garbage collection directive.