Virtual first logical volumes are provided to a host, a virtual second logical volume correlated with any one of the first logical volumes is created in a storage node in correlation with a storage control module disposed in the storage node, a correspondence relationship between the first and second logical volumes is managed as mapping information, a storage node which is an assigning distribution of an I/O request is specified on the basis of the mapping information in a case where the I/O request in which the first logical volume is designated as an I/O destination is given from the host, the I/O request is assigned to the storage control module of its own node in a case where the specified storage node is its own node, and the I/O request is assigned to another storage node in a case where the specified storage node is another storage node.

The disclosed embodiments disclose techniques for managing metadata and data storage for a cloud controller in a distributed filesystem. Two or more cloud controllers collectively manage distributed filesystem data that is stored in one or more cloud storage systems. More specifically, the cloud controllers cache and ensure data consistency for the data stored in the cloud storage systems, with each cloud controller maintaining (e.g., storing) in a local storage device: (1) one or more metadata regions containing a metadata hierarchy that reflects the current state of the distributed filesystem; and (2) cached data for the distributed filesystem. During operation, the cloud controller receives an incremental metadata snapshot that references new data written to the distributed filesystem. The cloud controller stores updated metadata from this incremental metadata snapshot in one of the metadata regions on the local storage device.

A storage system includes a first storage controller including a plurality of main storage media and one or more processor cores, and a second storage controller including a plurality of main storage media and one or more processor cores and performing communication with the first storage controller. Storage areas of the main storage media in the first storage controller are allocated to an address map. In response to the occurrence of failures in one or mode main storage media of the main storage media of the first storage controller, the first storage controller performs restarting to reallocate the storage areas of the main storage media excluding one or more main storage media having caused the failures to an address map reduced than before the occurrence of the failures. The second storage controller continues operating during the restarting of the first storage controller.

Managing an application's resource stack, including: detecting, in dependence upon one or more storage system metrics, an occurrence of a storage system performance anomaly; and responsive to detecting the storage system performance anomaly, identifying, in dependence upon codified relationships between one or more storage system metrics and one or more elements in the application stack that are external to the storage system, a root cause of the storage system performance anomaly.

Systems and methods for redundant object storage are disclosed. A method may include storing at least two copies of each of a plurality of objects among a plurality of nodes communicatively coupled to one another in order to provide redundancy of each of the plurality of objects in the event of a fault of one of the plurality of nodes. The method may also include monitoring access to each object to determine a frequency of access for each object. The method may additionally include redistributing one or more of the copies of the objects such that at least one particular node of the plurality of nodes includes copies of only objects accessed at a frequency below a predetermined frequency threshold based on the determined frequency of access for each object. The method may further include placing the at least one particular node in a reduced-power mode.

A controller monitors access frequencies of address ranges mapped to a data storage array. Based on the monitoring, the controller identifies frequently accessed ones of the address ranges that have lower associated wear, for example, those that are read more often than written. In response to the identifying, the controller initiates copying of a dataset associated with the identified address ranges from the data storage array to a spare storage device while refraining from copying other data from the data storage array onto the spare storage device. The controller directs read input/output operations (IOPs) targeting the identified address ranges to be serviced by access to the spare storage device. In response to a failure of a failed storage device among the plurality of primary storage devices, the controller rebuilds contents of the failed storage device on the spare storage device in place of the dataset associated with the identified address ranges.

Provided are a computer program product, system, and method for providing track format information when mirroring updated tracks from a primary storage system to a secondary storage system. The primary storage system determines a track to mirror to the secondary storage system and determines whether there is track format information for the track to mirror. The track format information indicates a format and layout of data in the track, indicated in track metadata for the track. The primary storage system sends the track format information to the secondary storage system, in response to determining there is the track format information and mirrors the track to mirror to the secondary storage system. The secondary storage system uses the track format information for the track in the secondary cache when processing a read or write request to the mirrored track.

Systems and methods are provided for local analytics for high-availability storage systems. A storage system may include first and second storage controllers to act as active and passive controllers for the storage system, and a plurality of storage devices. A method may include obtaining one or more storage microservices; responsive to determining that the second storage controller is not performing read and write operations on the storage device as the active controller, beginning to perform read and write operations on the storage device as the active controller; and responsive to determining that the second storage controller is performing read and write operations on the storage device as the active controller, executing the one or more storage microservices in the respective virtual computing environments of the storage system.

A data processing method and device, and a distributed storage system are described. The method and device are applied in a dual-control storage server. The dual-control storage server comprises two controllers. If one controller fails due to abnormalities, the other controller determines the storage device managed by the failed controller, and the other controller scans the data in the determined storage device to obtain the metadata of the storage device, and uses the metadata to read the data stored in the determined storage device. It can be seen that in this solution, if one controller is abnormal, the other controller will take the place of the failed controller to provide external services. This improves the stability of the data storage by the dual-control storage server.

A method for dispatching of service requests in a redundant storage virtualization subsystem including a plurality of storage virtualization controllers is disclosed. The method comprises the steps of the host entity issuing a first service request to a first one of the SVCs; the first SVC handling the first service request, acquiring a first result of servicing the first service request, and returning the first result to the host entity the result; and, the host entity issuing a second service request to a second one of the SVCs; and, the second SVC handling the second service request, acquiring a second result of servicing the second service request, and returning the second result to the host entity the result. A storage virtualization subsystem implementing the method, a computer system comprising such storage virtualization subsystem, and a storage media having machine-executable codes stored therein for performing the method are also disclosed.