A system and method for improving storage system performance by maintaining data integrity during bulk export to a cloud system is provided. A backup host reads a selected volume from the storage system via an I/O channel. The storage system remains online during bulk export and tracks I/O to the selected volume in a tracking log. The backup host compresses, encrypts, and calculates a checksum for each data block of the volume before writing a corresponding data object to export devices and sending a checksum data object to the cloud system. The devices are shipped to the cloud system, which imports the data objects and calculates a checksum for each. The storage system compares the imported checksums with the checksums in the checksum data object, and adds data blocks to the tracking log when errors are detected. An incremental backup is performed based on the contents of the tracking log.

Embodiments of the present disclosure enable high availability and performance in view of storage controller failure. A storage system includes three or more controllers that may be distributed in a plurality of enclosures. The controllers are in high availability pairs on a per volume basis, with volumes and corresponding mirror targets distributed throughout the storage system. When a controller fails, other controllers in the system detect the failure and assess whether one or more volumes and/or mirror targets are affected. If no volumes/mirror targets are affected, then write-back caching continues. If volume ownership is affected, then a new volume owner is selected so that write-back caching may continue. If mirror target ownership is affected, then a new mirror target is selected so that write-back caching may continue. As a result, write-back caching availability is increased to provide low latency and high throughput in degraded mode as in other modes.

Upon receiving, from application software, a first request for writing data stored in a first storage-region of the application software, an apparatus acquires a second storage-region, and copies the data to the second storage-region. The apparatus transmits, to one of drivers associated with each of redundant storage-devices on which mirroring is to be performed, a second request for writing the copied data to the each redundant storage-device, transmits, to the application software, a response indicating that writing of the data has been successfully performed in a case where a data-writing process for at least one of the redundant storage-devices is completed when a predetermined time has elapsed after the second request is transmitted to the drivers and before a retry-over time at which retry of the data-writing process is performed predetermined times, and excludes, from the redundant storage-devices, a storage-device for which the data-writing process is not completed.

In accordance with embodiments of the present disclosure, a system may include a first storage controller for managing a Redundant Array of Independent Disks (RAID) comprising a plurality of disk drives and a second storage controller for managing at least one disk drive other than the plurality of disk drives. The first storage controller may be configured to: (i) in response to the RAID having a degraded state and the first storage controller not having an available hot spare disk drive local to the first storage controller, communicate a request for a hot spare disk drive of another storage controller; (ii) receive a response to the request identifying a disk drive of the second storage controller as an alternative available hot spare disk drive; and (iii) communicate with the second storage controller to use the alternative available hot spare disk drive to rebuild the RAID.

An illustrative data storage management system is aware that certain data storage resources for storing/serving primary data operate in a partnered configuration. Illustrative components of the data storage management system analyze the failover status of the partnered primary data storage resources to determine which is currently serving/storing primary data and/or snapshots targeted for backup. When detecting that a first partnered primary data storage resource has failed over to a second primary data storage resource, the example storage manager changes the assignment of backup resources that are pre-administered for the targeted data. Accordingly, the example storage manager assigns backup resources, including at least one media agent, that are associated with the second primary data storage resource, and which are “closer” thereto from a geography and/or network topology perspective, even if the pre-administered backup resources are available for backup.

One or more aspects of the present disclosure relate to recovering at least one failed disk. In embodiments, determining a storage reserve capacity allocated for recovering at least one storage device of a storage array is determined. Zero or more storage portions from each storage device of at least one storage cluster for disk recovery are adaptively assigned based on the storage reserve capacity. The failing and/or failed disk using the assigned storage portions is recovered in response to detecting a failing and/or failed disk.

A virtualized copy-by-reference includes: receiving, from a first computer system, a request for reference information for source data within a source volume; providing, to the first computer system, the reference information, wherein the reference information corresponds to a metadata representation of the source data; receiving, from a second computer system, a request to write the source data to a target volume, and wherein the request to write the source data indicates the reference information; and copying, using the reference information, the metadata representation of the source data to the target volume.

A method for storing data may include receiving user data at a group of storage devices, wherein the storage devices are interconnected, erasure coding the user data into redundancy blocks at the group of storage devices, and storing the redundancy blocks on at least two of the storage devices. The erasure encoding may be distributed among at least two of the storage devices. The redundancy blocks may be arranged in reliability groups. The redundancy blocks may be grouped by the storage devices independently of the partitioning of the user data by the user. The method may further include recovering data based on redundancy blocks. A storage device may include a storage medium, a network interface configured to communicate with one or more other storage devices, and a storage processing unit configured to erasure code user data into redundancy blocks cooperatively with the one or more other storage devices.

An illustrative data storage management system is aware that certain data storage resources for storing/serving primary data operate in a partnered configuration. Illustrative components of the data storage management system analyze the failover status of the partnered primary data storage resources to determine which is currently serving/storing primary data and/or snapshots targeted for backup. When detecting that a first partnered primary data storage resource has failed over to a second primary data storage resource, the example storage manager changes the assignment of backup resources that are pre-administered for the targeted data. Accordingly, the example storage manager assigns backup resources, including at least one media agent, that are associated with the second primary data storage resource, and which are “closer” thereto from a geography and/or network topology perspective, even if the pre-administered backup resources are available for backup.

A storage system with storage drives and a processing device establishes resiliency groups of storage system resources. The storage system determines an explicit trade-off between data survivability over resource failures and data capacity efficiency, for the resiliency groups. Responsive to adding at least one storage drive, the storage system establishes re-formed resiliency groups according to the explicit trade-off, without decreasing data survivability. The storage system may bias to have more and narrower resiliency groups to increase mean time to data loss.