Techniques involve: detecting whether a first set of disks include an inaccessible disk, respective disk sections in the first set of disks forming a first set of stripes; in response to detecting the first set of disks including the inaccessible disk, determining faulty stripes in the first set of stripes, the faulty stripes including a first number of inaccessible disk sections; and in response to the first number exceeding a second number of free sections of the first set of disks, moving data in at least one stripe in the first set of stripes to free sections of the second set of disks to release sections of the at least one stripe, respective disk sections in the second set of disks forming a second set of stripes, each stripe in the first set of stripes and the second set of stripes having the same number of sections.

Data protection systems and techniques that include: receiving data for storage in a non-volatile memory (NVM) array having a total number of physical packages that includes a number of spare physical packages, wherein each one of the physical packages is mapped to one of a plurality of logical packages; storing a respective portion of component codewords on the non-spare physical packages; and in response to one of the non-spare physical packages failing, dynamically remapping the failed physical package to one of the logical packages mapped to one of the available spare physical packages. In an aspect, reading at least the failed physical package and inserting virtual zeros into the respective portion of the component codewords corresponding to the failed physical package; performing erasure decoding to recover the data from the failed package; and rewriting the recovered data from the failed package into the one of the available spare physical packages.

The efficiency of the maintenance of a storage apparatus including a plurality of flash drives can be enhanced. In a storage apparatus including a plurality of SSDs and a CPU, the CPU specifies, based on lifetimes of the SSDs depending on amounts of data written to the SSDs, the SSD to be replaced on a scheduled maintenance date, gives notice of the SSD specified to be replaced, and copies data in the SSD to be replaced to another SSD by the scheduled maintenance date on which the replacement is to be performed.

A storage apparatus includes a plurality of drives and has a parity group constituted by a plurality of drives. The storage apparatus stores a hash management table to manage hash values of a prescribed data unit of data of the drives constituting the parity group and a hash value of a prescribed data unit of data stored in another drive other than the drives constituting the parity group. A processor is configured to determine whether a same data unit as a data unit included in data stored in a replacement target drive exists in the other drive on a basis of the hash values, and copy the same data unit of the other drive to a replacement destination drive when the same data unit exists.

This disclosure describes techniques that include implementing network-efficient data durability or data reliability coding on a network. In one example, this disclosure describes a method that includes generating a plurality of data fragments from a set of data to enable reconstruction of the set of data from a subset of the plurality of data fragments; storing, across a plurality of nodes in a network, the plurality of data fragments, wherein storing the plurality of data fragments includes storing the first fragment at a first node and the second fragment at a second node; and generating, by the first node, a plurality of secondary fragments derived from the first fragment to enable reconstruction of the first fragment from a subset of the plurality of secondary fragments; and storing the plurality of secondary fragments from the first fragment across a plurality of storage devices included within the first node.

Managed drives of a storage node with different size drives in a fixed arithmetic relationship are organized into clusters of same size drives. Every drive is configured to have M*G same-size partitions, where M is a positive integer variable defined by the arithmetic relationship and G is the RAID group size. The storage capacity of all drives can be viewed as matrices of G+1 rows and M*G columns, and each matrix is composed of submatrices of G+1 rows and G columns. Diagonal spare partitions are allocated and distributed in the same pattern over groups of G columns of all matrices, for increasing partition index values. Members of RAID groups are vertically distributed such that the members of a given RAID group reside in a single partition index of a single cluster. When a drive fails, protection group members of the failed drive are rebuilt in order on spare partitions characterized by lowest partition indices for increasing drive numbers across multiple clusters. Consequently, drive access for rebuild is parallelized and latency is reduced.

Systems, methods, and circuitries are provided for supporting distributed erasure coding in a shared file system. In one example, a method is provided to be performed by an initiator device configured to read and write data in files stored in a plurality of storage nodes that are controlled by a file management system. The method includes generating a stripe by identifying data to be stored in a storage system; dividing the data into K data segments; and performing an erasure encoding operation on the K data segments to generate a parity segment, wherein the stripe includes the K data segments and the parity segment. The method includes requesting, from the file management system, respective memory allocations in the storage devices for storing respective segments of the stripe; and transmitting, to each of the plurality of storage nodes, a respective instruction to store a respective data or parity segment in the memory allocation on the respective storage device.

In general, embodiments relate to a managing a Redundant Array of Independent Disks (RAID) group. The embodiments include determining a minimum and maximum set of spare disks to allocate to the RAID group, wherein the RAID group comprises a plurality of active members, allocating the minimum number of spare members to the RAID group, allocating an additional spare member to the RAID group, setting a mode of the additional spare member to storage mode, enabling, after the setting, the RAID controller to store data in the plurality of active members and in the additional spare member, wherein the plurality of active members, the minimum number of spare members, and the additional spare member comprise persistent storage.

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.

A data recovery method for a storage medium, a data recovery system, and a related device are provided. The method includes: when a write failure occurs during writing data into the storage medium, extracting original data corresponding to the data failed to be written and original verification data in an original RAID stripe to which the original data belongs; obtaining new verification data by performing calculation on the original data and the original verification data by using a preset verification algorithm; forming a new RAID stripe by using valid data other than the original data in the original RAID stripe and the new verification data, and recording data relations in the new RAID stripe; and when a reading failure occurs during reading the data in the new RAID stripe, recovering, according to the data relations in the new RAID stripe, the data failed to be read.