Abstract: Each CM includes an interface unit, a first detection unit, and a reset control unit. The interface unit is configured to be connected to a communication channel and control communication using the communication channel. The first detection unit is configured to detect an abnormality in an inter-CM path including the interface unit of the CM, to which the first detection unit belongs, the interface unit of the other CM, and the communication channel. The reset control unit is configured to retract the other CM and reset the interface unit of the one CM in a case where an abnormality of the other CM side is detected by the first detection unit. Accordingly, even in a case where a suspicious control unit in which an abnormality has occurred is erroneously specified, the maintenance of the suspicious control unit can be performed with the operation being continued.

Abstract: A method for determining priority of recovery for a RAID implementation includes detecting a first failure of the RAID implementation; detecting a second failure of the RAID implementation; assigning a first priority to the first failure and a second priority to the second failure; and setting the priority of the recovery based on the first priority and the second priority.

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: An apparatus comprising a plurality of storage nodes comprising a plurality of corresponding storage disks and configured to store data in a distributed manner between the storage disks that achieves a Redundant Array of Independent Disks-0 (RAID0) like performance based on positioning information and without indexing the distributed data. A network component comprising a storage disk configured to maintain a plurality of physical files for different user data that are mapped to different volumes, wherein the volumes are distributed between the storage disk and a second storage disk based on a RAID0 like data distribution scheme without being indexed.

Abstract: For write cache protection of purpose built backup appliances in a computing environment, backup data of the write cache is created using a server memory that includes the write cache in a redundant array of independent disks (RAID) system. The server memory is not controlled by a failing RAID card and/or NVRAM card that controls the write cache. The backup data in the server memory is flushed to a persistent storage device subsequent to detecting a failure of the write cache for enabling recovery of the backup data using the persistent storage device during a reboot operation.

Abstract: A method begins, as data objects are ingested, by determining, for each of some of the data objects, a priority indicator to produce a listing of priority indicators. The method continues for a data object by determining encoding parameters based on a corresponding priority indicator. The method continues by encoding the data object in accordance with the encoding parameters to produce a plurality of sets of encoded data slices and storing them. The method continues by identifying a first data object for analysis based on a corresponding priority indicator and an analysis priority. The method continues by decoding a plurality of sets of encoded data slices to recover the first data object and analyzing it in accordance with analysis criteria to determine its relevancy. The method continues by issuing a command to delete the plurality of sets of encoded data slices when the relevancy is below a threshold.

Abstract: [This invention] inhibits the response time of the storage control apparatus from being longer even if the response time of the storage apparatus is long. The disk adapter (DKA), receiving a read message from the channel adapter (CHA), sets the timeout time in accordance with specified conditions, and tries to read data from the storage apparatus 4. As the timeout time, either the normal value or the shortened value is selected. If a timeout error occurs, the read job is reset, and correction read is started.

Abstract: A storage system has a RAID group configured by storage media, a system controller with a processor, a buffer memory coupled to storage devices and the processor by a communication network, and a cache memory coupled to the processor and the buffer memory by the network. A processor that stores first data, which is related to a write request from a host computer, in a cache memory, specifies a first storage device for storing data before update, which is data obtained before updating the first data, and transfers the first data to the specified first storage device. A first device controller transmits the first data and second data based on the data before update, from the first storage device to the system controller. The processor stores the second data in the buffer memory, specifies a second storage device, and transfers the stored second data to the specified second storage device.

Abstract: A disk control apparatus includes a processor, and a memory coupled to the processor in which executes a process as follows. The process includes diagnosing whether or not a failure has occurred on each of a plurality of disk apparatuses, determining, when the failure has occurred, whether or not the failure is a pre-defined failure, and excluding from diagnosis targets, when the failure is the pre-defined failure, a disk apparatus group included in a RAID together with a failed disk apparatus that is determined to have the pre-defined failure in the plurality of disk apparatuses.

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 data request for a solid state memory; identifying a logical block grouping corresponding to the data request, wherein the logical block grouping indicates physical data storage blocks spanning at least two distinct memory units of the solid state memory; reading stored data and parity information from at least a portion of the physical data storage blocks spanning the at least two distinct memory units; and recovering data of at least one block of the logical block grouping based on the stored data and the parity information.

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: Techniques for a data storage cluster and a method for maintaining and updating reliability data and reducing data communication between nodes, are disclosed herein. Each data object is written to a single data zone on a data node within the data storage cluster. Each data object includes one or more data chunks, and the data chunks of a data object are written to a data node in an append-only log format. When parity is determined for a reliability group including the data zone, there is no need to transmit data from other data nodes where the rest of data zones of the reliability group reside. Thus, inter-node data communication for determining reliability data is reduced.

Abstract: A method that includes identifying a failure indication for a first data storage device that is a member of a first RAID group within a storage array. The method further can include, via a processor external to the storage array, identifying a virtual drive that is defined to include at least one logical storage volume defined in a second RAID group. The virtual drive can be provisioned to serve as a virtual hot spare within the first RAID group to replace the first data storage device.

Abstract: A method includes a DSN access token module retrieving one or more 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 the computing device and/or the DSN access token module decoding the one or more 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. The method continues with the computing device and/or the DSN access token module generating a plurality of sets of data access requests in accordance with the DS error coding function. The method continues with the computing device sending the plurality of sets of data access requests to the DSN memory.

Abstract: A method that includes identifying a failure indication for a first data storage device that is a member of a first RAID group within a storage array. The method further can include, via a processor external to the storage array, identifying a virtual drive that is defined to include at least one logical storage volume defined in a second RAID group. The virtual drive can be provisioned to serve as a virtual hot spare within the first RAID group to replace the first data storage device.

Abstract: The present data storage system employs a memory controller with embedded logic to selectively XOR incoming data with data written in the memory to generate XOR parity data. The memory controller automatically performs XOR operations on incoming data based upon the address range associated with the memory “write” request. The system provides data migration and parity generation in a simple and effective manner and attains reduction in cost and power consumption. The memory controller may be built on the basis of FPGAs, thus providing an economical and miniature system.

Abstract: A storage device which includes a plurality of magnetic disk drives has a storage unit that stores, for each of the plurality of magnetic disk drives, information of whether or not the magnetic disk drive is incorporated in a redundant structure, a specifying unit that specifies, among the plurality of magnetic disk drives, a plurality of magnetic disk drives which have a redundant structure on the basis of the information stored in the storage unit, and a control unit that controls, for the plurality of magnetic disk drives specified by the specifying unit, an execution timing of sweep operation in which a head smoothes a lubricant material such that the sweep operation is executed for a single magnetic disk drive at a time.

Abstract: A method and system for reducing replication factor in a file system are provided. In some embodiments, two or more requested files may be grouped together under a leaf directory for RAID process. All data under the directory are grouped into one or more data stripes, each of which comprises a plurality of data blocks. One or more parity data blocks may be generated for each data stripe according to a computing algorithm, such as an exclusive OR (XOR) code or a Reed-Solomon (RS) code. Parity blocks corresponding to the one or more data stripes are concatenated into one parity file. Data blocks of the two or more requested files and their corresponding parity blocks are stored in separate partitions and/or separate storage drives of the file system.

Abstract: A method and a storage server for backing up data, involves mass storage devices of users of the service that connect to the storage server of the service provider over a public data network. The customers store the data with their terminals. The data is stored to the file system of the mass storage device which encrypts the stored data and transfers the data in encrypted form over the public data network to the storage server. The storage server calculates error correction data from the encrypted data. The error correction data is stored in the mass memory of the storage server. When recovering the stored data of the users, the storage server requests the stored data of all the users whose data was used for the error correction data calculation over the public data network to be used for the recovery calculation.

Abstract: A RAID bad block module is added to a RAID controller. The bad block module intercepts bad block errors and marks them in a bad block table. When a bad block error is intercepted the bad block module logs the error and determines, based on the error and previously received errors logged in the table, whether the RAID controller can handle the error without failing the entire array. If so, the bad block module passes the error to the RAID controller. Else, the bad block module passes the error to an application or operating system where it is handled like any other disk error. Thus, instead of failing the entire array, the bad block errors are dealt with by the operating system.

Abstract: A method begins by a dispersed storage (DS) processing module identifying a plurality of encoded data slices requiring rebuilding. The method continues with the DS processing module determining an amount of reserve memory required for storage of rebuilt slices for the identified plurality of encoded data slices requiring rebuilding. The method continues with the DS processing module updating memory utilization information to include the amount of reserve memory required. The method continues with the DS processing module indicating the memory utilization. The method continues with the DS processing module obtaining rebuilt slices. The method continues with the DS processing module storing the rebuilt slices in the memory and updating the memory utilization information.

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: A storage control apparatus manages a plurality of storage devices which belong to a RAID Logical Unit (RLU) such that data is made redundant between different storage devices, where RAID stands for Redundant Arrays of Independent Disks. If a first storage device fails, a rebuild controller executes a rebuild process to store the same data as recorded in the first storage device in a spare storage device. When the rebuild controller executing the rebuild process has failed in reading out data from a second storage device, a data recovery controller restarts the first storage device, and reads out data to be stored in the spare storage device from the restarted first storage device.

Abstract: A disk array redundancy controller ensures integrity of a mirrored or RAID storage array supporting a host system and minimizes recovery time responsive to a storage volume failure by traversing caches of recently written blocks to identify partially flushed stripes of data and recovering the inconsistent stripes on each of the storage volumes based on a master copy derived from the scan of all pre-failure caches of the storage array. The storage array employs nonvolatile caches in conjunction with solid state drive (SSD) storage volumes, allowing post-failure recovery of recently written blocks. A cache depth at least sufficient to store the largest stripe, or set of blocks, from the host ensures recovery of the entire stripe from a collective scan of the caches of all storage volumes of the storage array.

Abstract: Systems and methods are disclosed that allow for transparently recovering from an uncorrected multi-bit error of arbitrary length located at a memory address. Storing one or more parity pages, for a set of pages in system memory, such that a page in the set of pages may be reconstructed using one of the parity pages is disclosed. Storing an indication of one or more page'disk location such that the one or more pages may be reconstructed by refilling the page from disk is also disclosed.

Abstract: Disclosed herein are RAID backup management systems and methods. According to an aspect, a method may include identifying portions of data in each of multiple storage units of a RAID system. The method may also include backing up data in the identified portions to a hot spare. Further, the method may include allocating storage space in the hot spare for the backup based on detection of errors among the storage units.

Abstract: The present invention is related to systems and methods for harmonizing testing and using a storage media. As an example, a data system is set forth that includes: a data decoder circuit, a data processing circuit, and a write circuit. The data decoder circuit is configured to decode a test data set to yield a result. The data processing circuit is configured to encode a user data set guided by the result to yield a codeword. The write circuit is configured to store an information set corresponding to the codeword to a storage medium.

Abstract: A storage apparatus includes a plurality of first storage mediums in which data is redundantly stored and a controller. The controller includes a formatting section which performs formatting in each of the plurality of first storage mediums, a detection section which detects a failure that has occurred in the plurality of first storage mediums, a control section which makes the formatting section stop the formatting at the time of the detection of the failure by the detection section and which rebuilds the data stored in the plurality of first storage mediums in which the failure has occurred in a second storage medium other than the plurality of first storage mediums, and a rebuild processing section which rebuilds the data stored in the plurality of first storage mediums in the second storage medium in accordance with instructions from the control section.

Abstract: Since the whole storage device is blocked according to the conventional data saving method when failure occurs to the storage device in a storage subsystem, so that when failure occurs to two storage devices at the same time within a same RAID group, double failure is caused and data loss occurs. In order to solve the problem, the present invention divides a storage device into storage areas of predetermined units, constructs RAID groups from two or more storage areas, and when failure occurs to the storage area, selects a data migration destination storage area from either the RAID group in which failure has occurred or the RAID group other than the RAID group in which failure has occurred, migrates the data stored in the storage area where failure has occurred to the selected data migration destination storage area, and blocks only the storage area where failure has occurred.

Abstract: For preventing data loss in storage systems a detection is made that a storage device in a plurality of storage devices is experiencing a malfunction. The type of malfunction is determined. A SMART rebuilding technique, a normal building technique, a data migration technique, or a user data backup technique is selected to preserve the data in the storage device based on the determined type of the malfunction. The selected technique is performed on the storage device.

Abstract: For preventing data loss in storage systems, a detection is made that a storage device in a plurality of storage devices is experiencing a malfunction. The type of malfunction is determined. A SMART rebuilding technique, a normal building technique, a data migration technique, or a user data backup technique is selected to preserve the data in the storage device based on the determined type of the malfunction. The selected technique is performed on the storage device.

Abstract: The present invention achieves appropriate power saving of the storage systems in accordance with the user's needs.

Abstract: A method begins by a processing module receiving a data storage request, wherein the data storage request includes data and a data identifier (ID). The method continues with the processing module dispersed storage error encoding the data to produce a set of encoded data slices and determining a data dispersed storage network (DSN) address. The method continues with the processing module sending the set of encoded data slices to a DSN memory for storage at the data DSN address and updating a directory file with path information corresponding to the data ID and the data DSN address to produce an updated directory file. The method continues with the processing module dispersed storage error encoding the updated directory file to produce a set of encoded updated directory slices and sending the set of encoded updated directory slices to the DSN memory for storage at a directory DSN address.

Abstract: Systems and methods are provided that may be used to identify and report multiple information units (e.g., logical blocks) having medium errors within a given composite information structure (e.g., physical block) of a storage device (e.g., such as a hard drive) whenever any single information unit having an error within the same composite information structure is accessed.

Abstract: Proposed are concepts for rebuilding data in a data storage system. Embodiments rebuild data in order of priority as defined by a rebuild policy. Data rebuilding may therefore be undertaken so that important data is rebuilt before less important data for example. For instance, according to one embodiment, a method of rebuilding data in a data storage system includes: determining data to be rebuilt; identifying a plurality of data blocks, each data block comprising data to be rebuilt having a common characteristic; assigning a priority to each of the plurality of data blocks in accordance with a rebuild policy representing a priority to be assigned to a data block based on the common characteristic of its data; and rebuilding the data of each the plurality of data blocks in order of their assigned priority.

Abstract: An array can include a controller and multiple storage devices of a first type. When a storage device of the first type is replaced by a replacement storage device of a second type, and other storage devices of the first type remain in the array, the controller instructs the replacement storage device to configure itself as a storage device of the first type. When the last storage device of the first type in the array is replaced by a replacement storage device of the second type, the controller instructs all the storage devices of the array to configure themselves as storage devices of the second type.

Abstract: A method and a storage system are provided for implementing a sustained large block random write performance mechanism for shingled magnetic recording (SMR) drives in a redundant array of inexpensive disks (RAID). A Solid State Drive (SSD) is provided with the SMR drives in the RAID. The SSD is used in a hot spare mode, which is activated when a large block random-write event is identified for a SMR drive in the RAID. In the hot spare mode, the SSD temporarily receives new incoming writes for the identified SMR drive. Then the identified SMR drive is updated from the SSD to restore the state of the identified SMR drive, and operations continue with normal writing only using the SMR drives in the RAID.

Abstract: A computing device includes a central processing unit (CPU) and a memory system module. The CPU includes a data dispersed storage error coding (DSEC) module operable to DSEC decode a set of encoded ingress data slices to recapture ingress data and DSEC encode egress data to produce a set of encoded egress data slices, an instruction DSEC module operable to DSEC decode a set of encoded instruction slices to recapture an instruction, and an arithmetic logic unit (ALU) operable to, execute the instruction on the ingress data and execute the instruction to produce the egress data. The memory system module is operable to coordinate retrieval of the set of encoded ingress data slices from memory, coordinate retrieval of the set of encoded instruction slices from the memory, and coordinate storage of the set of encoded egress data slices in the memory.

Abstract: A method begins by identifying a storage unit of a set of storage units within a dispersed storage system as being likely to fail. The method continues by determining an approach for minimizing rebuilding the encoded data slices that are stored on an identified storage unit in an event of a failure of the identified storage unit. The approach is at least one approach option from a list of approach options that includes fostering new encoded data slices, replicating existing encoded data slices, and re-dispersing existing encoded data slices. The method continues by implementing the approach regarding the identified storage unit and when the identified storage unit fails, retrieving the encoded data slices that were stored on the identified storage unit based on the approach.

Abstract: A method begins by a dispersed storage (DS) processing module of a dispersed storage network (DSN) monitoring network traffic within the DSN. When the network traffic compares unfavorably to a desired network traffic function, the method continues with the DS processing module reducing a portion of the network traffic due to rebuilding flagged encoded data slices by at least one of changing rebuilding criteria for the flagged encoded data slices and changing rebuilding network traffic protocols.

Abstract: A failure of at least one of a plurality of drives of a redundant array of independent disks (RAID) is determined. A remainder of the plurality of drives of the RAID are remapped. A RAID level of the RAID is maintained, if the remainder of the plurality of drives are remapped.

Abstract: A computer system includes a management server which includes an acquisition unit for acquiring the configuration information and performance information of the storage apparatus and the host computer respectively at different timings, and a comparison unit for comparing, when a configuration change of the storage apparatus is commanded externally, a performance value of components in the storage apparatus subject to the configuration change and a performance value of components in a connection relationship with the components. The acquisition unit determines that an unknown component has been added in the storage apparatus when the difference in the performance values compared with the comparison unit exceeds a predetermined threshold, and reacquires configuration information from the storage apparatus.

Abstract: A storage processor includes storage for redundantly storing a log file of a journaling file system on a separate logical device from a primary copy of the log file and further provides for recovery of the file system upon failure of both the primary storage and the redundant storage storing the log file of the journaling file system by storing dirtied metadata objects in the cache of the storage processor to a vault area and then applying the stored dirtied metadata objects against the underlying persistent storage.

Abstract: A storage server resizes an array of mass storage devices and distributes data blocks stored in the array of mass storage devices evenly in a declustered organization across the resized array of mass storage devices. Resizing the array of mass storage devices may include adding a new mass storage device to the array or removing a mass storage device from the array. During resizing a data block is moved from one mass storage device to another mass storage device to minimize the imbalance of parity groups shared by the new mass storage devices in the array, as well as minimize the number of data blocks to be moved to uniformly balance the load across the new mass storage device.

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: In a dispersed storage network where slices of secure user data are stored on geographically separated storage units (44), a managing unit (18) connected to the network (20) may seek to broadcast and update secure access control list information across the network (20). Upon a target device (e.g., devices 12, 14, 16, 18, or 44) receiving the broadcast the target device creates and sends an access control list change notification message to all other system devices that should have received the same broadcast if the broadcast is a valid request to update access control list information. The target device waits for responses from the other system devices to validate that the broadcast has been properly sent to a threshold number of other system devices before taking action to operationally change local data in accordance with the broadcast.

Abstract: A method begins by a processing module determining that a data storage request is a cloud data storage request. The method continues with the processing module determining at least one of a cloud storage access reliability indication and a cloud storage data reliability indication for the data storage request. The method continues with the processing module sending the data storage request and the at least one of cloud storage access reliability indication and cloud storage data reliability indication to a cloud storage system.

Abstract: A storage device is detected as being decoupled from an apparatus. At least one partition of the storage device is part of a storage volume that includes an array of separate storage devices in an initial configuration prior to being decoupled. In response to the storage device being recoupled to the apparatus, a universally unique identifier (UUID) of the storage device is detected. In response to determining the UUID of the storage device was previously associated with the storage volume, the storage volume is reconfigured/restored to include the at least one partition of the storage device in the initial configuration.

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: A data access request is received specifying a data block stored in a stripe of a parity group that includes a plurality of data storage devices to store data blocks and a parity storage device to store parity information for the data. The stripe includes a data block from each of the plurality of data storage devices and the stripe includes a parity block from the parity storage device. An error is detected in the data block specified by the data access request. The error is identified as a lost write error for the data block or a lost write error for the parity block. Identifying the error includes comparing a first storage device signature stored in a metadata field associated with the data block to a second storage device signature stored in a label block identifying a data storage device where the data block is stored.