Techniques for storage management involve: determining expected usage time of a first storage disk in a set of storage disks, at least a part of the set of storage disks being configured to form at least one redundant array of independent disks (RAID); moving data in a first storage block, associated with a first RAID in the at least one RAID, in the first storage disk to a second storage block in a second storage disk in the set of storage disks based on a determination that the expected usage time is less than a predetermined threshold value; and replacing the first storage block with the second storage block, so that the second storage block is associated with the first RAID. Based on this manner, the stability of a storage system can be improved.

A method for proactively rebuilding user data in a plurality of storage nodes of a storage cluster is provided. The method includes distributing user data and metadata throughout the plurality of storage nodes such that the plurality of storage nodes can read the user data, using erasure coding, despite loss of two of the storage nodes. The method includes determining that one of the storage nodes is unreachable and determining to rebuild the user data for the one of the storage nodes that is unreachable. The method includes reading the user data across a remainder of the plurality of storage nodes, using the erasure coding and writing the user data across the remainder of the plurality of storage nodes, using the erasure coding. A plurality of storage nodes within a single chassis that can proactively rebuild the user data stored within the storage nodes is also provided.

A system and method for distributing data over a plurality of remote storage nodes. Data are split into segments and each segment is encoded into a number of codeword chunks. None of the codeword chunks contains any of the segments. Each codeword chunk is packaged with at least one encoding parameter and identifier, and metadata are generated for at least one file and for related segments of the at least one file. The metadata contains information to reconstruct from the segments, and information for reconstructing from corresponding packages. Further, metadata are encoded into package(s), and correspond to a respective security level and a protection against storage node failure. A plurality of packages are assigned to remote storage nodes to optimize workload distribution. Each package is transmitted to at least one respective storage node as a function iteratively accessing and retrieving the packages of metadata and file data.

A method of data recovery for a distributed storage system is a method of recovering multiple failed nodes concurrently with the minimum feasible bandwidth when failed nodes exist in a distributed storage system. By means of selecting assistant nodes, obtaining helper data sub-blocks through computing the selected assistant nodes, then computing a repair matrix and finally multiple the repair matrix and the helper data sub-blocks, the missing data blocks are reconstructed; or the missing data blocks are reconstructed by decoding. The method is applicable to data recovery in the case of any number of failed nodes and any reasonable combinations of coding parameters. The data recovery herein can reach the theoretical lower limit of the minimum recovery bandwidth.

A method of performing a reconstruction of data in a redundant array of independent disks (RAID) system with a protection pool of storage units includes receiving a request to perform a reconstruction of a first set of physical extents stored on a first physical disk of a set of physical disks. Each physical extent of the first set of physical extents is associated with an array of a second set of physical extents. The second set of physical extents is distributed across the set of physical disks. The method further includes allocating a third set of physical extents on one or more physical disks of the set of physical disks other than the first physical disk, and distributing data from each of the first set of physical extents of the first physical disk to a corresponding physical extent of the third set of physical extents.

A storage system comprises a plurality of storage nodes each comprising one or more storage devices and a processor coupled to a memory. The storage system is configured to store data blocks across the storage devices of the storage nodes utilizing a redundant array of independent disks (RAID) arrangement. At least a given one of the storage nodes is configured to store a plurality of RAID metadata bitmaps in persistent storage of the storage node so as to be available for a recovery operation in the event of a detected failure, to identify a particular subset of the RAID metadata bitmaps to be updated in conjunction with an additional operation other than the recovery operation, and to temporarily store the identified subset of the RAID metadata bitmaps in the memory of the storage node in a manner determined based at least in part on an operation type of the additional operation.

Techniques for RAID reconstruction involve: determining, from a task list, multiple stripes in a RAID that are involved in a to-be-processed task within a current task window, the task list including an external I/O request task and an internal reconstruction I/O request task, and each stripe including data on a first number of data disks and data on a second number of parity disks; reading data from the multiple stripes into a read buffer; and if data of the first number of data disks in a stripe among the multiple stripes has already been read into the read buffer, performing the internal reconstruction I/O request task on the stripe. Such a technique helps to increase the processing power and efficiency of the data storage system to recover the reconstruction of RAID stripes while coping with external I/O requests.

Techniques for managing disks involve: determining, from multiple disks, a first disk set for providing redundant storage, the number of disks included in the first disk set being not less than a first threshold number that corresponds to the number of disks required to be included in a redundant array of independent disks; determining, based on the multiple disks, a candidate solution in which at least the first disk set is used to provide redundant storage; determining an unavailable capacity that the candidate solution will have; and determining, based on the unavailable capacity and the candidate solution, a target solution for providing the redundant storage. Accordingly, such techniques can promote efficient management of disks.

Techniques involve: determining, according to a determination that a performance level of a target storage unit is lower than a threshold level, whether idle disk slices that can be used for reconstructing malfunctioning disk slices in the target storage unit exist in a slice pool; determining a priority of the target storage unit according to a determination that the idle disk slices do not exist; and selecting replacing disk slices for reconstructing the malfunctioning disk slices from available storage units based at least in part on the priority, wherein the available storage units have performance levels not lower than the threshold level. In this way, data loss due to the off-line of storage units is prevented; and meanwhile, the performance of the entire storage system can be globally stabilized.

A method includes acquiring, by a managing unit of a dispersed storage network (DSN), storage unit status information and data object storage status information from a plurality of storage units of DSN memory of the DSN. The method further includes determining, by the managing unit, DSN status information of the DSN memory based on the storage unit status information and the data object storage status information. The method further includes identifying, by the managing unit, DSN memory issues within the DSN memory. The method further includes prioritizing, by the managing unit, corrective remedies for the DSN memory issues based on the status information of the DSN memory. The method further includes facilitating, by the managing unit, the execution of the prioritized corrective remedies to correct the DSN memory issues.