Abstract: Techniques perform failure recovery of a storage device. The techniques involve: determining, based on failure data indicating at least one failed disk, whether the at least one failed disk comprises a system disk associated with an extent pool of the storage device, the extent pool being built based on system disks and user disks; in response to determining that the at least one failed disk comprises a system disk, rebuilding the user data of the system disk to one or more further disks associated with the extent pool; and in response to the system disk being replaced with an updated system disk, restoring the rebuilt user data from the one or more further disks to the updated system disk, an association of the system disk with the extent pool being maintained until the system disk is replaced by the updated system disk.

Abstract: Technology for synchronizing event handling between a primary storage processor and a secondary storage processor in an active/active data storage system. A single working task descriptor is selected at a time for uninterruptible execution, from a task scheduling queue that is maintained only on the primary storage processor. A copy of the working task descriptor is transmitted to the secondary storage processor. The working task descriptor is executed on both the primary storage processor and the secondary storage processor and without interruption by execution of any other task descriptor. Execution of the working task descriptor includes simultaneously transitioning through individual task states on both the primary storage processor and the secondary storage processor, and simultaneously executing functions on both the primary storage processor and the secondary storage processor during associated task states.

Abstract: Embodiments of the present invention relate to a method and system for managing a memory in a storage system. In one embodiment of the present invention, there is provided a method for managing a memory in a storage system. The storage system comprises a first controller, a first memory and a first additional memory that is coupled to the first controller. The method comprises: in response to an access request on the storage system from the first controller hitting the first memory, allocating a storage space in the first additional memory; writing data associated with the access request in the first memory to the storage space allocated in the first additional memory; and serving the access request via the storage space allocated in the first additional memory. In another embodiment of the present invention there is further proposed a system for managing a memory in a storage system.

Abstract: Embodiments of the present disclosure relate to a method and device for flushing pages from a solid-state storage device. Specifically, the present disclosure discloses a method of flushing pages from a solid-state storage device comprising: determining a first number based on a period length of one flushing cycle and a period length required for building one flushing transaction, the first number indicating a maximum number of flushing transactions that can be built in the flushing cycle; and flushing pages from the solid-state storage device with an upper limit of the first number in the flushing cycle. The present disclosure also discloses a device for flushing pages from a solid-state storage device and a computer program product for implementing steps of a method of flushing pages from a solid-state storage device.

Abstract: The present disclosure relates to an apparatus for a data storage device, an adapter, an array controller, a data storage device, and a relevant method. The apparatus for the data storage device comprises: a power management module configured to detect power-off of a power supply and to switch to a backup battery unit in the data storage device in response to detecting the power supply. The apparatus is configured to cause the backup battery unit to supply power only to the volatile memory in the data storage device. By using a solution according to the present disclosure, for example, preserving time for data may be prolonged in the case of power-off.

Abstract: The present disclosure provides a method and apparatus for online reducing cache devices from a cache. The cache includes a first cache device and a second cache device, the method comprising: keeping the cache and the second cache device in an enabled state; labeling the first cache device as a to-be-reduced device so as to block a new data page from being promoted to the first cache device; removing a cached data page from the first cache device; removing the cached input output (IO) historical information from the first cache device; and removing the first cache device from the cache. There is also provided a corresponding apparatus.

Abstract: A method is used in validating data in a storage system. The method writes host data to the storage system during processing of a host I/O operation, where the host is in communication with the storage system. The storage system writes host data and test data associated with the host data to a storage device of the storage system. The method reads the host data and the test data from the storage device for validating the host data, and evaluates the test data to determine whether the host data has been written correctly by the storage system to the storage device. Upon determining that the host data has not been written correctly by the storage system to the storage device due to a failure, the method evaluates the test data to determine a cause of the failure.

Abstract: Embodiments of the present invention provide a method and a system for managing a storage system. In one embodiment of the present invention, there is provided a method for managing a storage system, where the storage system comprises a first controller, a second controller, a first communication area as well as a second communication area.

Abstract: Embodiments of the present disclosure relate to a method and apparatus for facilitating wear leveling of a solid state disk (SSD). The method comprises obtaining a performance parameter of a SSD device of a plurality of SSD devices in the SSD cache, and the SSD device includes one or more SSD disks. The method further comprises determining a weight for the SSD device based on the performance parameter of the SSD device. The method also comprises setting reserved space for the SSD device according to the weight for the SSD device, and the reserved space is inaccessible in the SSD device.

Abstract: Embodiments of the present disclosure provide a method, an apparatus and a computer program product for managing an input/output (I/O). The method comprises, in response to receiving a first I/O request of a first type for a storage device, determining whether there exits at least one credit available to the first type of I/O requests. Each of the at least one credit indicates I/O processing capability reserved by the storage device for the first type of I/O requests. The method further comprises allocating a first credit to the first I/O request based on a result of the determining. The method further comprises performing, by using the first credit, an I/O operation requested by the first I/O request on the storage device. Moreover, the method further comprises, in response to completion of the I/O operation, recycling the first credit for use by a subsequent I/O request. Embodiments of the present disclosure can implement dynamic allocation of I/O processing capability for different types of I/Os.

Abstract: Techniques perform data recovery. The techniques involve: in response to receiving to-be-written data at a first cache module, storing metadata in the data into a first non-volatile cache of the first cache module. The techniques further involve storing user data in the data into a first volatile cache of the first cache module. The techniques further involve sending the metadata and the user data to a second cache module for performing data recovery on the user data. Accordingly, a larger and better guaranteed data storage space may be provided to a cache data backup/recovery system without a need to increase the battery supply capacity and even without a battery.

Abstract: Techniques manage a storage system comprising a group of storage devices. The techniques involve: determining from the group of storage devices a first storage device which is in a rebuilding state; in response to a second storage device in the group of storage devices failing, obtaining a recoverability indication indicating whether a data block in the second storage device, which corresponds to a target data block in the first storage device, is recoverable or not on the basis of a data state of the target data block; and recovering data in the data block in the second storage device corresponding to the target data block on the basis of the recoverability indication.

Abstract: In certain techniques, a size of a storage space in a first storage device that is allocated for write requests is determined. Write requests are issued by a control device of the storage system to store data into the first storage device and are waiting to be completed. A predetermined release rate of releasing the data stored in the first storage device to a second storage device is determined. An access speed of the first storage device is greater than that of the second storage device. A predetermined completion time of the write requests is determined based on the size of the storage space and the predetermined release rate, and in response to the predetermined completion time exceeding a predetermined time threshold, a throttling indication is transmitted to the control device such that the control device throttles issuing of a further write request for the first storage device.

Abstract: Techniques expand storage space. Such techniques can create a storage stripe group during a shuffling operation after a storage device being added, without waiting for full completion of the shuffling operation. Such techniques can effectively reduce the waiting time for creating the storage stripe group. Besides, such techniques can support partial mapping of the storage stripe group, such that the storage resources mapped to the storage stripe group can be rapidly utilized.

Abstract: A method and a system for locking a storage area in a storage system. There is provided a method for locking a storage system in a storage system, where the storage system comprises a first controller, a second controller, a first communication area and a second communication area. The method comprises: a first lock flag associated with the storage area is written to the first communication area in response to receiving at the first controller a data access request with respect to the storage area, where the first communication area being readable and writable to the first controller and being readable to the second controller. A second lock flag associated with the storage area is read from the second communication area, where the second communication area being readable to the first controller and being readable and writable to the second controller. The storage area is locked by the first controller in response to the second lock flag indicating that the storage area is not locked by the second controller.

Abstract: Embodiments of the present disclosure relate to a method and an apparatus for operating a hybrid storage device, the hybrid storage device including a storage device of a first type and a storage device of a second type that is different from the first type, the method comprising: synchronously writing data in the storage device of the first type and the storage device of the second type. By using the embodiments of the present disclosure, the actual storage space may be increased, and the service life of the storage device may be prolonged.

Abstract: Embodiments of the present disclosure relate to methods, devices and computer program products for writing data in a disk array in a storage system. The storage system comprises a disk array. The method comprises: in response to receiving a write request to write new data to a data block in at least one disk array group in a degraded mode within a disk array, reading old data stored in the data block and old parity information stored in a parity block associated with the data block. The method further comprises: determining new parity information associated with the new data based on the old data, the old parity information and the new data. The method further comprises: writing the new data and the new parity information into at least one cache page provided by a cache component in the storage system, the at least one cache page being allocated in a persistent memory in the cache component.

Abstract: A data storage system has multi-core processing circuitry and processes data movement requests using a multi-threaded library component having an initial operation of invoking an underlying driver to read data, and subsequent operations of copying data, invoking an underlying driver to write data, and initiating additional data movement operations as necessary to complete data movement for an entire range of the data movement request. Core-affined threads are used to execute library component operations for data movement requests of associated per-core queues. Data movement requests are distributed among the per-core queues for parallel processing of the data movement requests by the respective core-affined threads, and the execution of a core-affined thread includes initially starting the thread on the affined core to perform the initial operation, and subsequently re-starting the thread on the affined core to perform each of the subsequent operations.

Abstract: Embodiments of the present disclosure provide a method, device and computer program product for cache management. The method includes: receiving from a storage device an indication for an invalid storage block in the storage device; in response to receiving the indication, looking up a cache page associated with the invalid storage block in the cache; in response to finding the cache page in the cache, determining validity of data in the cache page; and in response to the data being invalid, reclaiming the cache page.

Abstract: A method, computer program product, and computer system for receiving, by a computing device, an I/O request, wherein the I/O request may include host I/O priority information. It may be determined that the I/O request is associated with a token bucket of a plurality of token buckets based upon, at least in part, the host I/O priority information. If the token bucket of the plurality of token buckets has sufficient tokens for the I/O request, the I/O request may be sent down a block stack for processing, and if the token bucket of the plurality of token buckets has insufficient tokens for the I/O request, the I/O request may be rejected.