Abstract: Disclosed is a method and system for saving the copybacked data in a drive and continuing to rebuild on the same drive where the copy back was in progress when the online drive, where the copy back is not initiated, fails.

Abstract: Optimization of a RAID volume is described. In an example, a method of optimizing a redundant array of independent disks (RAID) volume includes: identifying a RAID level used for a plurality of disks in the RAID volume; defining a relation among rebuild rate, scrub rate, and annualized data loss event rate (ADLER) for the RAID volume using constant values and the RAID level; selecting a value for the ADLER; applying a policy to the relation to choose a value for one of the rebuild rate or the scrub rate; and determining a value for the other of the rebuild rate or the scrub rate from the relation using the value of the rebuild rate or the scrub rate as determined from the policy.

Abstract: A method and system of optimizing the performance, capacity and data redundancy in a storage system by defining the LBA range on each storage element managing that corresponding range (slice) on each device using a data protection method optimized for the performance and level of data protection required. The creation of such a storage array along with the replacement of failed elements and the expansion of the capacity through the addition of additional elements is managed is an automatic and transparent manner.

Abstract: A method begins by a processing module receiving data to store and determining error coding dispersal storage function parameters. The method continues with the processing module encoding at least a portion of the data in accordance with the error coding dispersal storage function parameters to produce a set of data slices. The method continues with the processing module defining addressable storage sectors within the single hard drive based on a number of data slices within the set of data slices to produce a set of addressable storage sectors. The method continues with the processing module storing data slices of the set of data slices in corresponding addressable storage sectors of the set of addressable storage sectors.

Abstract: A method begins with a processing module receiving an access request for the data object. The method continues by ascertaining that the data object is divided into a plurality of data segments and that plurality of data segments are dispersed storage error encoded to produce a plurality of sets of encoded data slices. The method continues by ascertaining batching of the plurality of sets of encoded data slices, wherein the plurality of sets of encoded data slices are arranged into a set of batched encoded data slices. The method continues by outputting a set of access requests for the set of batched encoded data slices to storage units of the DSN.

Abstract: A method begins by a computing device determining that dispersed storage network (DSN) memory is to be accessed regarding data. The method continues when the computing device is paired with a DSN access token module with the DSN access token module retrieving a plurality of sets of at least a threshold number of dispersed storage (DS) error coding function slices from the DSN memory via the computing device. The method continues with at least one of the computing device and the DSN access token module decoding the plurality of sets of the at least a threshold number of DS error coding function slices using a default DS error coding function to recapture a DS error coding function and executing, by one or more of the computing device and the DSN access token module, the DS error coding function to access the DSN memory regarding the data.

Abstract: A method and system for manipulating a spin state of each disk in a drive array is disclosed. In one embodiment, a method includes monitoring input/output (I/O) requests to each disk drive in a disk array and identifying any disk drive as an inactive disk drive based on a number of I/O requests directed to said any disk drive for a given time interval. The method further includes moving data from the inactive disk drive to an active disk drive having a free disk space to store the data and updating metadata associated with the data using a log-structured file system for the disk array. Further, the method includes manipulating a spin state of the inactive disk drive by spinning down the inactive disk drive to conserve power. Furthermore, the method includes redirecting subsequent I/O requests for the inactive disk drive to the active disk drive by accessing the metadata of the log-structured file system.

Abstract: Out-of-order reconstruction of a RAID storage device at a replacement storage device enables the replacement storage device to execute I/O for reconstructed regions during reconstruction of the replacement storage device. In one embodiment, the failed storage device is analyzed to find recoverable information, which is copied to the replacement storage device to reduce the need for reconstruction. In another embodiment, the priority for region's reconstruction is increased upon detection of an I/O to the region. The I/O is queued until reconstruction of the region and then executed after reconstruction of that region so that I/O at the region need not be repeated during reconstruction of the remainder of the replacement storage device.

Abstract: The present disclosure includes systems and techniques relating to implementing fault tolerant data storage in solid state memory. In some implementations, a method includes receiving a request for data stored in a solid state memory, and identifying a logical block grouping for logical data blocks of the requested data, the logical data blocks corresponding to the solid state memory, and the logical block grouping comprising at least one physical data storage block from two or more solid state physical memory devices. The method also includes reading the stored data and a code stored in the identified logical block grouping, and comparing the code to the stored data to assess the requested data.

Abstract: The present invention reduces the amount of rebuild processing and executes a rebuild process efficiently. Multiple storage devices configure a parity group. Of the multiple storage devices, a prescribed storage device in which a failure has occurred is blocked. Each storage device stores management information. The management information manages from among the storage areas of the storage device a prescribed area having data from a higher-level apparatus. A controller determines whether a storage area of the prescribed storage device is the prescribed area based on the management information, and executes a rebuild process with respect to the area determined to be the prescribed area.

Abstract: A method for improving the performance of a RAID under rebuild is disclosed. In one embodiment, such a method includes identifying a RAID requiring rebuild, such as by identifying a RAID having one or more failed storage-drive components. The method then automatically performs the following in response to identifying the RAID: the method identifies hot extents (i.e., extents most heavily accessed) in the RAID; the method migrates the hot extents from the identified failed RAID to a normal RAID not requiring rebuild, such as to an underused RAID; and the method rebuilds the failed RAID. The migration of the hot extents will ideally occur while the RAID is being rebuilt but may also be performed prior to the rebuild process. A corresponding apparatus and computer program product are also disclosed.

Abstract: A system includes a write module, a read module, and a parity module. The write module is configured to modify first user data stored on a first member of a redundant array of independent disks (RAID) using second user data. The read module is configured to read the first user data and first parity data corresponding to the first user data from a solid-state disk associated with the RAID if at least one of the first user data and the first parity data are stored on the solid-state disk, or from the RAID if the at least one of the first user data and the first parity data are not stored on the solid-state disk. The parity module is configured to generate second parity data based on the first user data, the second user data, and the first parity data.

Abstract: A method begins by a first device of a dispersed storage network (DSN), when a number of successful write requests of a set of write requests is equal to or greater than a threshold number but less than all, identifying one or more unsuccessful write requests of the set of write requests. The method continues with first device sending the one or more unsuccessful write requests to an auxiliary writing unit of the DSN. The method continues with the auxiliary writing unit, for an unsuccessful write request, identifying a storage unit of the DSN to produce an identified storage unit, sending the unsuccessful write request to the identified storage unit, and verifying successful execution of the unsuccessful write request by the identified storage unit.

Abstract: A method begins a first rebuilder application identifying a data slice having a storage error. The method continues with the first rebuilder application or a second rebuilder application identifying a data segment based on the identified data slice. The method continues with the second rebuilder application identifying one or more other slice servers that are storing other data slices of the encoded data segment. The method continues with the second rebuilder application receiving a sufficient number of the other data slices to reconstruct the data segment and decoding them to reconstruct the data segment. The method continues with the second rebuilder application encoding the reconstructed data segment in accordance with the information dispersal algorithm to produce a new set of data slices and selecting one of them as the rebuild data slice.

Abstract: Server supervisor processes in the segment nodes of a database cluster afford transparent reset mechanisms to a fault tolerant service (FTS). FTS probes only primary segments as to their status unless a primary segment does not respond, in which case FTS will probe the mirror of that primary-mirror pair, and change the state of the mirror to primary if the primary is faulty. Only a primary segment to initiate a reset of its mirror segment and then resets itself. If a mirror segment fails, it shuts down and its corresponding primary segment will report the failure to FTS. Transient communication failures are addressed by retry logic on FTS probing, and not reported to FTS. Reset is not initiated by FTS and preserves the segment state in the absence of errors.

Abstract: A storage control device for managing data in a storage while maintaining redundancy of the data includes a formatting management table, a formatting processing section, a recovery management table and a recovery processing section. The formatting management table manages a formatted region and an unformatted region in a management target volume. The formatting processing section executes formatting of the unformatted region in the management target volume on the basis of the formatting management table. The recovery management table retains a content of the formatting management table at a point of occurrence of a redundancy restoration event when a redundancy restoration event has occurred during formatting. The recovery processing section executes recovery of a formatted region, which had been formatted at the point of occurrence of the redundancy restoration event, on the basis of the recovery management table in parallel with the formatting.

Abstract: A system and method for performing power conservation actions is described. In some examples, the system determines a power conservation policy based on information from the system, and implements that policy in an enterprise or in one or more buildings, such as within a data storage environment. In some examples, the system adds or modifies global filters or system performance based on information from the system.

Abstract: Systems and methods are disclosed for recovering from a data access error encountered in data stripes implemented in a data redundancy scheme (e.g., RAID) in a solid state storage device. In one embodiment, the storage device holds parity data in a temporary, volatile memory such as a RAM and writes the parity data to the non-volatile memory when a full stripe's worth of new write data has been written to the non-volatile memory. In one embodiment, upon detecting that a data access error has occurred in a partially written stripe, the storage device initiates a write of the parity data for the partially written stripe to the non-volatile memory and executes a RAID recovery procedure using the newly written parity data to attempt to recover from the detected error. This approach allows for a recovery from the data access error without waiting for the full stripe to be written.

Abstract: A storage area managing apparatus includes a managing unit for managing a plurality of logical volumes provided by a plurality of storage drive groups for storing data redundantly, and a rebuilding controller for generating recovery data when at least one of the drive groups is degraded on the basis of the data stored in the degraded drive group and generating a selected logical volume on the basis of the capacity of the recovery data, the rebuilding controller controlling the management unit for managing first logical volumes to correspond to a part of the plurality of storage drive groups except for the degraded drive group. The storage area managing apparatus includes a first transferring unit for transferring the recovery data to the part of the plurality of storage drive groups as indicated by the selected logical volume.

Abstract: In one embodiment of the invention, a flash-based/solid-state storage system with an implemented data redundancy scheme such as RAID is configured to hold parity data in a volatile memory such as RAM and write such parity data to the non-volatile flash media when a full stripe of data has been written to the media. Other embodiments in certain situations force an early write of the parity for a partial stripe that has not been fully written to the non-volatile media. Those situations may include a data access error on data in a partial stripe and a detected power loss event with a partial stripe present. Embodiments are directed to writing additional data with the parity data for the partial stripe and then later using the additional data in data recovery. This approach allows the controller to easily detect the presence of a partial stripe and handle such a stripe accordingly.

Abstract: A storage system assigns one or more large disks in a storage enclosure as a common dedicated hot spare that is used by multiple RAID groups. Storage space equivalent to the smallest physical disk in a RAID group is allocated on the common dedicated hot spare. A mapping of this allocated storage space to the RAID group is maintained in nonvolatile memory. When a disk fails in the RAID group, the allocated storage space on the common dedicated hot spare receives a rebuild of the failed disk. Once the rebuild is complete, the allocated storage space acts as part of the RAID group. When the failed disk is replaced, the data on the allocated storage space is copied to the replacement disk. Once the copy is complete, the allocated storage space is once again set to act as a dedicated hot spare to the RAID group.

Abstract: In one embodiment of the invention, a replaceable memory apparatus is disclosed. The replaceable memory apparatus includes a first rectangular multilayer printed circuit board having a first side and a second side opposite the first side; a first male pluggable electrical connector mounted to the first side near a first edge; a first female pluggable electrical connector mounted to the second side; and first non-volatile memory mounted to the first side and the second side. The first female pluggable electrical connector is coupled to the first male pluggable electrical connector to feed through first signals. The first non-volatile memory is coupled to the first female pluggable electrical connector and the first male pluggable electrical connector to receive the first signals.

Abstract: Methods and systems for data reconstruction following drive failures may include: storing data across two or more drives in one or more data stripes, each data stripe including two or more drive extents; detecting a degradation of a drive containing a drive extent associated with a first data stripe; assigning a reconstruction priority to the drive extent associated with the first data stripe; detecting a degradation of a drive containing a drive extent associated with a second data stripe; and assigning a reconstruction priority to the drive extent associated with the second data stripe.

Abstract: A processor copies first information stored in a first storage to a backup volume. The processor stores management information when a first piece of the first information is updated to second information after the copy. The processor executes, when a failure occurs in the first storage, first restoration based on the management information and reference information stored in reference storages other than the first storage. The first restoration restores the second information to a spare storage. The processor executes second restoration based on the management information and the reference information. The second restoration restores third information to the spare storage. The processor stops the second restoration when a failure occurs in a second storage while the second restoration is being executed. The processor executes third restoration based on the first information stored in the backup volume and the management information. The third restoration restores fourth information to the spare storage.

Abstract: A method begins by a processing module identifying sets of dispersed storage (DS) units for each of a plurality of dispersed storage networks (DSNs) in a computing system network, wherein a set of the sets of DS unit stores an error coded data file. The method continues with the processing module identifying a reference entity within the computing system network. The method continues with the processing module determining first data access performance information between the reference entity and a first one of the sets of DS units and determining second data access performance information between the reference entity and a second one of the sets of DS units for each of the plurality of DSNs. The method continues with the processing module storing the first and second data access performance information for each of the plurality of DSNs to produce system data access performance information.

Abstract: A method begins by a processing module receiving a data storage request that includes data and determining dispersed storage error encoding parameters for dispersed error encoding storage of data. The method continues with the processing module dispersed storage error encoding the data in accordance with the dispersed storage error encoding parameters to produce a set of encoded data slices and establishing access control information for each encoded data slice of the set encoded data slices in accordance with the dispersed storage error encoding parameters to produce a set of access control information. The method continues with the processing module appending a corresponding one of the set of access control information to each of the set of encoded data slices to produce a set of appended slices and outputting the set of appended slices to a set of dispersed storage units.

Abstract: A method for handling media errors during a read operation on a data storage device. The method comprises detecting that a first file and a second file are duplicates, wherein the first file is stored on a first storage device. Metadata is written to the first storage device in association with the first file, wherein the metadata identifies the location of the second file that is a duplicate of the first file. Later, an application program requests a first read operation to read the first file. In response to a media error that results from the first read operation, the method reads the metadata associated with the first file to identify the location of the second file, performs a second read operation to read the second file instead of the first file, and provides the second file to the application program in satisfaction of the requested first read operation.

Abstract: A method includes detecting that a first file and a second file are duplicates, and storing the first file and the second file to a target storage device. Metadata is written to the target storage device in association with the first file, wherein the metadata identifies the location of the second file that is a duplicate of the first file. Later, an application program requests a first read operation to read the first file. In response to a media error that results from the first read operation, the target storage device reads the metadata associated with the first file to identify the location of the second file, performs a second read operation to read the second file instead of the first file, and provides the second file to the application program in satisfaction of the requested first read operation.

Abstract: Technologies are described herein for achieving data consistency during a failover from a primary node to a secondary node in a storage cluster with a shared RAID array in a degraded mode. When the primary storage node receives a write I/O operation, a volume module on the primary node reads the missing data strip data from the failed disk belonging to the stripe targeted by the write I/O operation. The primary storage node communicates the missing data strip to the secondary storage node, which writes the missing strip data to an outstanding strip log. Upon the failure of the primary node, the secondary storage node reads the missing data strip from the outstanding strip log and writes the missing data strip to the shared RAID array, thus restoring data consistency to the stripe of the RAID array containing the missing data strip.

Abstract: A data control device includes: a switch portion that has a plurality of first terminals on an upstream side, a plurality of second terminals on a downstream side, and a circuit portion that optionally switches a connection between the first terminals and the second terminals based on an external switching signal; and at least one control portion that has a first input/output portion on the upstream side and a second input/output portion on the downstream side, wherein the second input/output portion is connected to the first terminal of the switch portion and the first input/output portion is connected to the second terminal of the switch portion, and wherein the at least one control portion controls an input/output of data between the first input/output portion and the second input/output portion.

Abstract: Recovery of a failed storage device of a RAID array to a replacement storage device is improved by initiating recovery before failure of the storage device occurs. If failure occurs before completing the transfer of all information from the failed storage device to the replacement storage device, then the RAID controller identifies untransferred information to recreate the failed storage device at the replacement storage device by re-building only the untransferred information with a parity operation using information stored at the array.

Abstract: Systems and methods are disclosed for storing the firmware and other data of a flash memory controller, such as using a RAID configuration across multiple flash memory devices or portions of a single memory device. In various embodiments, the firmware and other data used by a controller, and error correction information, such as parity information for RAID configuration, may be stored across multiple flash memory devices, multiple planes of a multi-plane flash memory device, or across multiple blocks or pages of a single flash memory device. The controller may detect the failure of a memory device or a portion thereof, and reconstruct the firmware and/or other data from the other memory devices or portions thereof.

Abstract: A method begins by a processing module receiving a data retrieval request and determining a read threshold number of dispersed storage (DS). The method continues with the processing module sending read request messages to DS units and receiving encoded data slices to produce received encoded data slices. The method continues with the processing module determining an incremental number of encoded data slices based on the number of received encoded data slices, determining an incremental number of DS units, and sending a read request message to each of the incremental number of DS units when the number of received encoded data slices compares unfavorably to a decode threshold number. The method continues with the processing module dispersed storage error decoding the received encoded data slices to produce data when the number of received encoded data slices compares favorably to the decode threshold number of encoded data slices.

Abstract: Storage system comprises a second storage apparatus, which is coupled to multiple first storage apparatuses and is of a different type from the first storage apparatuses, and a first control device, which exists either inside or outside of the second storage apparatus. Row of stripes comprising multiple data elements obtained by segmenting a prescribed data unit, and a redundancy code for rebuilding the data elements, is distributively stored in multiple first storage apparatuses, which are more numerous than the total number of stripe data elements, which are either the data elements or redundancy code, in the row of stripes. The row of stripes is configured to enable the rebuilding of the stripe data elements even when a failure has occurred in up to a prescribed allowable number, which is two or more, of the first storage apparatuses storing the stripe data elements of the relevant row of stripes.

Abstract: A method and system for manipulating a spin state of each disk in a drive array is disclosed. In one embodiment, a method includes monitoring input/output (I/O) requests to each disk drive in a disk array and identifying any disk drive as an inactive disk drive based on a number of I/O requests directed to said any disk drive for a given time interval. The method further includes moving data from the inactive disk drive to an active disk drive having a free disk space to store the data and updating metadata associated with the data using a log-structured file system for the disk array. Further, the method includes manipulating a spin state of the inactive disk drive by spinning down the inactive disk drive to conserve power. Furthermore, the method includes redirecting subsequent I/O requests for the inactive disk drive to the active disk drive by accessing the metadata of the log-structured file system.

Abstract: A duplicate-aware disk array (DADA) leaves duplicated content on the disk array largely unmodified, instead of removing duplicated content, and then uses these duplicates to improve system performance, reliability, and availability of the disk array. Several implementations disclosed herein are directed to the selection of one duplicate from among a plurality of duplicates to act as the proxy for the other duplicates found in the disk array. Certain implementations disclosed herein are directed to scrubbing latent sector errors (LSEs) on duplicate-aware disk arrays. Other implementations are directed to disk reconstruction/recovery on duplicate-aware disk arrays. Yet other implementations are directed to load balancing on duplicate-aware disk arrays.

Abstract: A non-volatile memory device includes first and second memory regions to store data and a memory control unit. Each of the first and second memory regions is configured by a plurality of physical pages. Each of the physical pages is configured by a plurality of regions corresponding to a plurality of logical addresses. The memory control unit performs control of batch erasing and batch writing on every physical page. When a first physical page in the first memory region includes a first region corresponding to a first logical address, which is a target to be written, and when a second physical page in the second memory region includes a second region corresponding to the first logical address, which is a target to be written, the memory control unit selects either the first physical page or the second physical page as a physical page for writing.

Abstract: Digital content from a source (e.g., a file or a stream), is striped and encoded in parallel over a cluster of Storage Systems. The encoding ensures that subsequent retrieval of the data succeeds even when some members of the cluster of Storage Systems are lost or when errors in communication result in the loss of some IP packets. Host Map File (HMF) data is produced that describes fully how to retrieve the content, including the encoding parameters, the cluster of Storage Systems and the striping of the encoded data. This HMF data is then inserted as the header of every encoded file on the cluster of Storage Systems. The HMF data is the only way the encoded files can be reassembled into a meaningful whole. The original content is retrieved by requesting its data from the cluster of Storage Systems. In each Storage System, a decoder parses the HMF data and transmits the striped data to the requestor. The decoders cooperate to dynamically detect erasures and to reconstruct the missing data.

Abstract: A redundant array of independent nodes are networked together. Each node executes an instance of an application that provides object-based storage. The nodes are grouped into a plurality of systems each having multiple nodes. An object recovery method comprises: receiving, by a first system of the plurality of systems from a client application, a read request for an object, the object having been replicated to/from at least one second system among the plurality of systems; if the object of the read request is available in the first system, returning by the first system the object of the read request to the client application; and if the object of the read request is not available in the first system, performing a read from replica process by the first system to access a replica of the object from a second system among the plurality of systems and using the replica of the object to return the object of the read request to the client application.

Abstract: A method begins by a processing module sending list digest requests to a set of dispersed storage (DS) units. The method continues with the processing module receiving list digest responses from at least some of the set of DS units and determining whether an inconsistency exists between first and second list digest responses of the list digest responses. The method continues with the processing module requesting at least a portion of each of the slice name information lists from first and second DS units of the set of DS units and identifying a slice name information error associated with the inconsistency based on the at least a portion of each of the slices name information lists of the first and second DS units when the inconsistency exists between first and second list digest responses of the list digest responses.

Abstract: A method begins by a processing module identifying a memory device having an expired useable memory life with respect to a legacy storage protocol. The method continues with the processing module extracting data from the memory device. The method continues with the processing module reprovisioning the memory device from the legacy storage protocol to a dispersed storage error coding storage protocol.

Abstract: A method begins by a dispersed storage (DS) processing module receiving data from a plurality of sources and queuing the data for storage in a dispersed storage network (DSN). The method continues with the DS processing module utilizing temporary dispersed storage error encoding parameters for efficient and reliable error encoded temporary storage of the data in the DSN. For a data object of the data temporarily stored in the DSN, the method continues with the DS processing module determining non-temporary storage parameters for the data object, retrieving first encoded data slices regarding the data object from the DSN, reconstructing the data object from the first encoded data slices in accordance with the temporary dispersed storage error encoding parameters, encoding the reconstructed data object in accordance with the non-temporary storage parameters for the data object to produce second encoded data slices, and storing the second encoded data slices in the DSN.

Abstract: According to this invention, a highly reliable memory device that uses up a life of a flash memory can be provided. The memory device is a nonvolatile memory device including a plurality of memory cells, in which: each of the plurality of memory cells is an FET which includes a floating gate; the plurality of memory cells are divided into a plurality of deletion blocks; and the nonvolatile memory device reads data stored in a first deletion block, detects and corrects an error contained in the read data, stores, when the number of bits of the detected error exceeds a threshold, the corrected data in a second deletion block, sets a smaller value as the threshold as an error frequency detected in the first deletion block is higher, and sets a smaller value as the threshold as the number of deletion times executed in the first deletion block is larger.

Abstract: An integrated circuit (IC) includes addressable blocks of memory, and at least one redundant block of memory. A block of memory includes two or more chunks of memory. The IC also includes redundancy control cells. Control circuitry is included to access a first chunk of a redundant block of memory in place of a first remapped chunk one of the addressable blocks of memory, and a second chunk of a redundant block of memory in place of a second remapped chunk one of the addressable blocks of memory, based on the redundancy control cells.

Abstract: A RAID device has a plurality of HDDs for a RAID configuration and controls the RAID configuration. The RAID device has a host that performs various data processes on the HDDs and a control unit that controls communication with the HDDs. With this configuration, if an initialization process for assigning physical addresses unique to the HDDs is performed, the RAID device receives initialization frames from the HDDs. Then, the RAID device detects abnormality of the HDDs in accordance with information contained in the received initialization frames.

Abstract: A method and system for providing advanced storage features using commodity, consumer-level storage devices is provided. The advanced storage system is a component that is connected between the computer system and one or more physical disk drives. The host interface of the advanced storage system presents itself to the computer system as a virtual disk drive that implements the commands of consumer-level storage hardware that are familiar to the host controller of the computer system. Similarly, the storage device interface of the advanced storage system presents itself to one or more disk drives as a consumer-level host controller, regardless of the actual topology of the physical storage devices that are connected. This system provides a simple way for a user to combine low-cost, consumer-level hardware to add advanced storage features to a computer system.

Abstract: A storage server stores data in a stripe of a parity group that includes a plurality of data storage devices to store data and a parity storage device to store parity information. The stripe includes a data block from each of the data storage devices and a parity block from the parity storage device. The storage server receives a data access request specifying a data block in the stripe, and a lost write detection module detects an error in the data block. The lost write detection module compares a first storage device signature stored in a metadata field associated with the data block to a second storage device signature stored in a global field of the data storage device containing the data block. If the first storage device signature matches the second storage device signature, the lost write detection module compares a consistency point count stored in the metadata field to a reconstructed consistency point count.

Abstract: In accordance with embodiments of the present disclosure, a system comprising may include a storage controller and a plurality of storage resources communicatively coupled to the storage controller. At least one storage resource of the storage resources may be capable of performing storage resource-level failure protection and configured to disable storage resource-level failure protection in response to a determination that the at least one storage resource is a member of a redundant storage array.

Abstract: A method and apparatus for rebuilding a data set. In accordance with some embodiments, a data storage device is coupled to a host. An error condition associated with a memory of the data storage device is detected. Data stored in a first portion of the memory unaffected by said error condition is transferred to the host. A communication signal is output to the host that indicates that data stored in a second portion of the memory affected by said error condition will not be transferred to the host. The host reconstructs the data stored in the second portion of the memory responsive to the communication signal.

Abstract: For each original data segment, a distributed storage processing unit generates encoded slices designed to prevent the original data segment from being reconstructed using fewer than a threshold number of encoded slices. Multiple encoded slices are generated for each of two different data segments, and the slices associated with the first and second data segment are stored substantially concurrently in different storage sets employing different distributed storage units. Encoded slices for even and odd data segments can be stored in different storage sets, or longer sequences of data segments can be stored in alternating storage sets. Storage sets can also be determined by the vault generation of a particular data segment.