Abstract: A high availability DAS system uses a solid state cache to provide near active-active performance in a DAS duster, while retaining the implementation simplicity of active-passive or dual active system. Each node in the duster may include a solid state cache that stores hot I/O in an active-active mode, which allows the data to be read from or written to the underlying dual-active or active/passive DAS RAID system only when access to the “hot Region” cools down or in the case of Cache Miss. The hot I/O data includes hot read data that accumulated dynamically regardless of ownership of the drives where the hot read data is permanently stored. The hot I/O data also includes hot write data that is mirrored across the solid state cache memories to avoid potential dirty write data conflicts and also to provide High Availability in case of server failures.

Abstract: Methods, apparatuses, and computer program products of extending cache in a multi-processor computer are provided.

Abstract: A method, system, and computer program product for restoring blocks of data stored at a corrupted data site using two or more mirror sites. The method commences by receiving a trigger event from a component within an application server environment where the trigger event indicates detection of a corrupted data site. The trigger is classified into at least one of a plurality of trigger event types, which trigger event type signals further processing for retrieving from at least two mirror sites, a first stored data block and a second stored data block corresponding to the same logical block identifier from the first mirror site. The retrieved blocks are compared to determine a match value, and when the match value is greater than a confidence threshold, then writing good data to the corrupted data site before performing consistency checks on blocks in physical or logical proximity to the corrupted data site.

Abstract: Systems, methods, and computer-readable and executable instructions are provided for computing system reliability. A method for computing system reliability can include storing, on one of a plurality of devices, a checkpoint of a current state associated with the one of the plurality of devices. The method may further include storing the checkpoint in an erasure-code group across the plurality of devices.

Abstract: An information processing apparatus connecting a plurality of hard disks rebuilds data stored in one hard disk of the plurality of hard disks to another hard disk of the plurality of hard disks. The information processing apparatus is controlled in such a manner that when the information processing started, the rebuild is not resumed immediately after the information processing apparatus is started, and the rebuild is resumed after a predetermined time has elapsed.

Abstract: An apparatus or method for operating a mirrored disk storage system, comprises a detector component operable to detect that a failure has left read stability in doubt, a determiner component for determining a repair characteristic of a pair of mirrored disks, a comparator for comparing the repair characteristic of a first of the pair with the repair characteristic of a second of the pair, and a selector for selecting one of the first or the second of the pair having a preferred repair characteristic to be used as a synchronization source disk. The preferred repair characteristic comprises the characteristic that no repair is required for the one of the first or the second of the pair, or that a least repair time is required for the one of the first or the second of the pair.

Abstract: In one embodiment, the present invention includes a method for receiving an indication of a loss of redundancy with respect to a pair of mirrored memory regions of a partially redundant memory system, determining new mirrored memory regions, and dynamically migrating information stored in the original mirrored memory regions to the new mirrored memory regions. Other embodiments are described and claimed.

Abstract: In one embodiment, the present invention provides an ability to handle an error occurring during a memory migration operation in a high availability system. In addition, a method can be used to dynamically remap a memory page stored in a non-mirrored memory region of memory to a mirrored memory region. This dynamic remapping may be responsive to a determination that the memory page has been accessed more than a threshold number of times, indicating a criticality of information on the page. Other embodiments are described and claimed.

Abstract: Dynamically replicated memory is usable to allocate new memory space from failed memory pages by pairing compatible failed memory pages to reuse otherwise unusable failed memory pages. Dynamically replicating memory involves detecting and recording memory faults, reclaiming failed memory pages for later use, recovering from detected memory faults, and scheduling access to replicated memory pages.

Abstract: A migration destination storage creates an expansion device for virtualizing a migration source logical unit. A host computer accesses an external volume by way of an access path of a migration destination logical unit, a migration destination storage, a migration source storage, and an external volume. After destaging all dirty data accumulated in the disk cache of the migration source storage to the external volume, an expansion device for virtualizing the external volume is mapped to the migration destination logical unit.

Abstract: Various embodiments of the present invention provide systems and methods for managing solid state drives. As an example, a storage system is described that include at least a first flash memory block and a second flash memory block, and a control circuit. The first flash memory block and the second flash memory block are addressable in the storage system. The control circuit is operable to identify the first flash memory block as partially failed, receive a write request directed to the first flash memory block; and direct the write request to the second flash memory block.

Abstract: A data volume rebuilder reduces the time required to reconstruct lost data in a RAID protected data volume operating with a failed physical disk drive. A data volume rebuilder uses the remaining functioning physical disk drives in the RAID protected data volume operating with the failed disk to regenerate the lost data and populate a virtual hot spare store allocated in a separate RAID protected data volume. The recovered data is distributed across the physical disk drives supporting the virtual hot spare store. Once the virtual hot spare store is populated, the data volume can recover from a subsequent failure of a second physical disk drive in either RAID group. After replacement of the failed physical disk drive, the data volume rebuilder moves the recovered data from the virtual hot spare store to the new physical disk drive.

Abstract: An apparatus and method to manage redundant non-volatile storage (“NVS”) data backups in a data storage system comprising (n) clusters, wherein each cluster comprises a processor and a cache, and wherein each cache comprises a first NVS portion and a second NVS portion, wherein the method configures, for each value of (i), a primary NVS backup for an (i)th cluster, where that (i)th primary NVS backup comprises a first NVS portion of a cache disposed in an (i+1)th modulo (n) cluster, wherein (i) is greater than or equal to 0 and less than (n). The method further configures, for each value of (i), a secondary NVS backup for an (i)th cluster, where that (i)th secondary NVS backup comprises a second NVS portion of a cache disposed in an (i+2)th modulo (n) cluster.

Abstract: The present invention provides a system and a method for utilizing a parity protection module to back up data on striped aggregates. Specifically, the system computes party data for data stored at a particular location of each of a plurality of constituent aggregates, and stores the parity on one of the constituent aggregates that is a parity owner for that particular location of data. In the event one of the constituent aggregates fails, new data may still be accessed by the system (the striped aggregates), both to write new data, and to read data stored on the failed aggregate. In particular, the parity protection module allows clients to read data from a failed aggregate by running a reverse parity computation, which may also be used to restore the data to the failed aggregate.

Abstract: A method for managing a redundant memory architecture for an information handling system (IHS) may include providing redundant memory for a portion of system memory wherein the redundant memory is configured to mirror data stored in the portion of system memory. The method may further include reporting a parameter associated with the portion of system memory to an operating system of the IHS and executing a program from the portion of system memory.

Abstract: Embodiments of methods of protecting RAID systems from multiple failures and such protected RAID systems are disclosed. More particularly, in certain embodiments of a distributed RAID system each data bank has a set of associated storage media and executes a similar distributed RAID application. The distributed RAID applications on each of the data banks coordinate among themselves to distribute and control data flow associated with implementing a level of RAID in conjunction with data stored on the associated storage media of the data banks. Furthermore, one or more levels of RAID may be implemented within one or more of the data banks comprising the distributed RAID system.

Abstract: The active server A101 notifies its own operating status to the administration server 106, and the administration server 106 acquires a snapshot and copies a disk according to the policy established by a user. When the active server A101 or the active disk 113 fails, the administration server 106 chooses a backup server A104 and a status storage disk A114 to be booted and restarts them by using the snapshot according to the policy.

Abstract: A non-volatile memory data storage system, comprising: a host interface for communicating with an external host; a main storage including a first plurality of flash memory devices, wherein each memory device includes a second plurality of memory blocks, and a third plurality of first stage controllers coupled to the first plurality of flash memory devices; and a second stage controller coupled to the host interface and the third plurality of first stage controller through an internal interface, the second stage controller being configured to perform RAID operation for data recovery according to at least one parity.

Abstract: A system (and method) for determining reconstruction formulas for partial strip reconstruction in a storage system in which a plurality of lost strips have been detected, includes using a combination of a direct reconstruction method and a sequential reconstruction method.

Abstract: A method for reducing data loss and unavailability by integrating multiple levels of a storage hierarchy is provided. The method includes receiving a read request. In addition, the method includes recognizing a data failure in response to the read request. The method further includes locating an alternate source of the data to be read in response to recognizing the data failure. The alternate source includes data cached at devices in the storage hierarchy, data in a backup system, and cumulative changes to the data since the last backup. Moreover, the method includes responding to the read request with data from the alternate source.

Abstract: There is provided a system including a cluster 11, a cluster 12 and an image server 20. A host 101a constituting the cluster 11 has a root file system 111a used to operate the host 101a in a local disk. The image server 20 has a root file system 221a used to operate the host 101a, and the host 101a virtually construct a root file system 121a by mounting the root file system 221a. When the root file system 111a is varied, the host 101a synchronizes the root file system 111a with the root file system 121a. The same applies to host 102a constituting the cluster 12.