A storage unit includes an interface configured to interface and communicate with a dispersed storage network (DSN), a memory that stores operational instructions, and processing circuitry. The storage unit receives a set of read slice requests for a set of encoded data slices (EDSs) associated with a data object stored within a first set of storage units, where the storage the first set of storage units includes the storage unit. When at least a read threshold number of EDSs and fewer than all of the set of EDSs can be successfully retrieved from the first set of storage units, the storage unit identifies at least one EDS associated with a data object that is stored in a second set of storage units, obtains the at least one EDS and stores the at least one EDS in the storage unit.

A plurality of storage nodes in a single chassis is provided. The plurality of storage nodes in the single chassis is configured to communicate together as a storage cluster. Each of the plurality of storage nodes includes nonvolatile solid-state memory for user data storage. The plurality of storage nodes is configured to distribute the user data and metadata associated with the user data throughout the plurality of storage nodes such that the plurality of storage nodes maintain the ability to read the user data, using erasure coding, despite a loss of two of the plurality of storage nodes. A plurality of compute nodes is included in the single chassis, each of the plurality of compute nodes is configured to communicate with the plurality of storage nodes. A method for accessing user data in a plurality of storage nodes having nonvolatile solid-state memory is also provided.

A data storage system includes a plurality of storage devices organized as a redundant array of inexpensive disks (RAID) storage array and a RAID controller. The RAID controller monitors the plurality of storage devices in the RAID storage array. The RAID controller also detects that a host read request of a host has a latency exceeding a latency threshold. Based on the monitoring, the RAID controller determines whether a proactive rebuild of a data requested by the host read request in absence of a data error would likely be beneficial to performance. Based on determining that a proactive rebuild of the data requested by the host read request would likely be beneficial to performance, the RAID controller initiates the proactive rebuild of the data and sends the requested data to the host.

A method includes identifying an independent data object of a plurality of independent data objects for retrieval from dispersed storage network (DSN) memory. The method further includes determining a mapping of the plurality of independent data objects into a data matrix, wherein the mapping is in accordance with the dispersed storage error encoding function. The method further includes identifying, based on the mapping, an encoded data slice of the set of encoded data slices corresponding to the independent data object. The method further includes sending a retrieval request to a storage unit of the DSN memory regarding the encoded data slice. When the encoded data slice is received, the method further includes decoding the encoding data slice in accordance with the dispersed storage error encoding function and the mapping to reproduce the independent data object.

An indication is received from a storage device that an attempt to read a portion of data from a block of the storage device has failed. A command is transmitted to the storage device to perform a scan on data stored at the block comprising the portion of data to acquire failure information associated with a plurality of subsets of the data stored at the block. The failure information associated with the plurality of subsets of the data stored at the block is received from the storage device.

Techniques for managing data involve receiving a write request to write a data block into a first stripe in a disk array, the write request comprising a first storage address for storing the data block. The techniques further involve determining, based on the first storage address, a first group of disks related to a data portion of the first stripe and a second group of disks related to a parity portion of the first stripe. The techniques further involve, in response to a first disk in the first group of disks being unavailable, storing a data sub-block related to the first disk into a first parity portion of the parity portion such that the data block is stored in the first stripe, the first parity portion being located at a second disk in the second group of disks. The techniques further involve returning a response to the write request, the response comprising a first indication indicating a status of the disks in the disk array.

A data transmission and protection system includes a plurality of solid-state drives (SSDs), a storage medium, a central processing unit (CPU) and a massively parallel processor (MPP). The storage medium storing an application program and a redundant array of independent disks (RAID) configuration. The CPU is coupled to the storage medium and configured to execute the application program to generate a virtual SSD interface for the plurality of SSDs according to the RAID configuration. The MPP is coupled to the virtual SSD interface and the plurality of SSDs. The MPP is configured to execute data exchange with the plurality of SSDs in response to a command received from the virtual SSD interface.

A method for execution by a distributed storage network begins by receiving a request to transfer a copy of a set of encoded data slices from at least some associated virtual storage vaults to a destination virtual storage vault and continues by determining whether the destination storage unit supports a source virtual storage vault of the at least some source virtual storage vaults. When the destination storage unit supports the source virtual storage vault the method continues by determining a sub-set of encoded data slices of the set of encoded data slices for transfer and finally, by facilitating sending the sub-set of encoded data slices to the destination storage unit.

Presented herein are methods, non-transitory computer readable media, and devices for selectively limiting the amount of data in a file system, which include: determining a reparity bit value for a write disk block range, wherein the reparity bit is configured to track a number of writes in progress to a stripe range; determining the reparity bit value; updating a threshold written disk block number as a highest disk block number of the reparity bit value; and initiating a RAID operation until it reaches the threshold written disk block number, wherein the threshold written disk block number comprises a maximum written disk block number representing the last disk block number written.

A method for execution by a dispersed storage and task (DST) client module includes issuing a read threshold number of read slice requests are issued to storage units of the set of storage units. One or more encoded slices of a selected read threshold number of encoded slices are received. When a next encoded data slice of a decode threshold number of encoded data slices is received within a response timeframe, outputting of the next encoded data slice is initiated. When the next encoded data slice is not received within the response timeframe, receiving of another decode threshold number of encoded slices of the set of encoded slices is facilitated. The other decode threshold number of encoded slices are decoded to produce recovered encoded data slices, where the recovered encoded data slices includes at least a recovered next encoded data. Outputting of the recovered next encoded data slice is initiated.