Abstract: Storage management techniques involve, in response to a request to write data to a redundant array of independent disks (RAID), determining whether there is an offline disk in a plurality of storage disks constituting the RAID, the RAID comprising a plurality of stripes, each of the plurality of stripes comprising a plurality of storage blocks divided from the plurality of storage disks; in response to determining that there is an offline disk in the plurality of storage disks, selecting a target stripe from the plurality of stripes, the target stripe having a storage block allocated from the offline disk for storing parity information; and writing the data to the target stripe. In this way, the performance of data write can be improved in presence of an offline disk. In addition, the performance of subsequent data read can also be improved potentially.

Abstract: Techniques are directed to reading data. Such techniques involve in response to receiving a read request for the target data, determining that target data is stored in both a first storage device and a second storage device. Such techniques further involve determining at least one of reliability and access load for each of the first storage device and the second storage device. Such techniques further involve: determining, based on the at least one of the reliability and the access load, one of the first storage device and the second storage device as a target storage device so as to respond to the read request. By means of certain techniques, at least one of the access load and service lives is balanced between storage devices so as to improve the efficiency of data read and the overall performance of a storage system.

Abstract: Embodiments of the present disclosure provide a method of managing a disk pool, the disk pool having a plurality of disks which are divided into a plurality of disk extents, the method comprising: determining the number of input/output (I/O) requests for disk extents in the disk pool within a predetermined period of time; determining respective hotness of the disk extents based on the number of I/O requests; determining hotness of the disks based on the hotness of the disk extents; and determining migration of data in the disk extents based on the hotness of the disk.

Abstract: Embodiments of the present disclosure relate to methods, devices and computer program products for managing a redundant array of independent disks (RAID). The method comprises: in response to a number of a plurality of disks occupied by the RAID exceeding a first threshold, determining a first number of disk pairs to be disassociated among the plurality of disks, the first number of disk pairs at least comprising a first disk and a second disk associated with each other, and a first extent in the first disk and a second extent in the second disk being included in a same RAID extent of the RAID. The method further comprises determining a third disk for migrating at least one of the first extent and the second extent among the plurality of disks. Besides, the method further comprises migrating the at least one extent to the third disk to disassociate the first disk and the second disk so that a second number of disk pairs associated with each other among the plurality of disks is below a second threshold.

Abstract: State information of one or more extents in a stripe in a storage system is obtained, the state information indicating whether the extents comprise at least one of a failed extent and an end-of-life extent. A risk level for the stripe is determined based on the state information, the risk level indicating a possibility that data stored in the stripe is lost. In response to the risk level exceeding a first threshold, the storage system is caused to: rebuild data corresponding to the failed extent, and write the data to a sparing extent in a second storage device different from a first storage device where the failed extent resides; and write data corresponding to the end-of-life extent to a swapped extent in a fourth storage device different from a third storage device where the end-of-life extent resides, the fourth storage device being used to replace the third storage device.

Abstract: A method, computer program product, and computer system for receiving, by a computing device, a request to create a heterogeneous storage object. A first storage object of the heterogeneous storage object may be created with a first RAID type. A second storage object of the heterogeneous storage object may be created with a second RAID type. The heterogeneous storage object may be persisted to a data store.

Abstract: Techniques for managing disks involve: in response to a number of a plurality of disks to be partitioned being greater than a predetermined number of disks in a disk set, determining a plurality of candidate combinations of disk sets from the plurality of disks. The techniques further involve selecting a target combination from the plurality of candidate combinations, a first disk set of the target combination comprising at least a first subset corresponding to a first disk array, a second disk set of the target combination comprising at least a second subset corresponding to a second disk array, a number of disks in the first subset and a number of disks in the second subset being both equal to a first number and the disks in the first subset being different from the disks in the second subset. Accordingly, such techniques improve the storage efficiency of the disk array.

Abstract: A method, computer program product, and computer system for identifying a bit for an allocation unit. It may be determined if data has been modified on the allocation unit while degraded. A rebuild of the allocation unit may be executed when the bit is a first value. The rebuild of the allocation unit may be skipped when the bit is a second value.

Abstract: Techniques involve: in accordance with a determination that a target disk in a set of disks is to be replaced, determining whether the target disk is a user disk for storing user data; in response to the target disk being the user disk, searching for a spare disk in the set of disks available for replacing the target disk; and in accordance with a determination whether the set of disks include a spare disk available for replacing the target disk, generating an indication of whether or not to provide a warning of replacing the target disk. Such techniques may more accurately provide warning of disk replacement.

Abstract: Techniques for providing information involve: obtaining, from a first device for updating information, a first copy of the updated information, where a second copy of the information prior to the updating is cached in a first buffer acting as an active buffer and the second copy is provided in response to receiving a first request for providing the information from a second device; caching the first copy in a second buffer acting as a standby buffer; in response to the first copy being cached in the second buffer, switching the second buffer to the active buffer and switching the first buffer to the standby buffer; and in response to receiving a second request for providing the information from the second device, providing, to the second device, the first copy cached in the active buffer. Such techniques can ensure the consistency of the provided information without a lock.

Abstract: A technique provides a RAID resiliency set from a plurality of storage devices. The technique involves identifying a minimum sub-RRS width based on a predefined RAID level to be enforced on the RRS. The technique further involves, based on the minimum sub-RRS width, allocating segments from the plurality of storage devices to create a maximum number of sub-RRSs. The technique further involves forming the RRS from the created maximum number of sub-RRSs.

Abstract: Techniques involve: determining corresponding valid metadata rates of a plurality of metadata blocks stored in a metadata storage area of a storage system, the valid metadata rate of each metadata block indicating a ratio of valid metadata in the metadata block to all metadata in the metadata block; selecting a predetermined number of metadata blocks having a valid metadata rate lower than a first valid metadata rate threshold from the plurality of metadata blocks; storing valid metadata in the predetermined number of metadata blocks into at least one metadata block following the plurality of metadata blocks in the metadata storage area; and making the valid metadata in the predetermined number of metadata blocks invalid. Accordingly, such techniques can improve the efficiency of the storage system.

Abstract: A storage system comprises a cache device and a storage device group. A technique involves: the cache device of the storage system receiving from a host an input/output (I/O) request for the storage system; and upon determining that the storage system is just recovered from a hardware failure and the storage device group in the storage system is in a ready but degraded state, safely performing data write/read by sending a new Recover State I/O request to the storage device group. Such a technique may be used to reduce a Data Lost window, reduce or avoid data loss. In addition, such a technique may be implemented in a current RAID technology, namely, can be used in combination with the current RAID technology.

Abstract: Various embodiments of the present disclosure generally relate to a method and a device for managing a hybrid storage disk array. Specifically, the method can include: in response to a first data portion of a first extent in a first set of extents of a first type of storage disk being unavailable, obtaining a metadata portion of a second extent in a second set of extents of the second type of storage disk. The method can also include: reading from the metadata portion reconstruction information for reconstructing the first data portion; and reconstructing, based on the reconstruction information, the first data portion on a third extent in the first set of extents. In addition, there is also provided accordingly a system, an apparatus and a computer program product.

Abstract: Techniques manage an encryption key in a storage system. The techniques involve: transmitting an encryption key request from a storage management component to a key management service component; obtaining, via the key management service component, an encryption key encrypted by the key management service component based on the encryption key request; providing the obtained encrypted encryption key to the storage management component; maintaining, in the storage management component, correspondence between the encrypted encryption key and a storage device; and registering, according to the correspondence, the encrypted encryption key corresponding to the storage device to an encryption hardware unit, such that the encryption hardware unit can decrypt the encrypted encryption key to obtain the encryption key corresponding to the storage device. Effective management of the encryption key is thus realized.

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: Embodiments of the present disclosure provide a method and a device for managing storage system. In an embodiment, a plurality of RAID stripes to be reconstructed in the storage system are determined. A first RAID stripe is selected from a plurality of RAID stripes based on a plurality of I/O load states at a disk extent level for the plurality of RAID stripes at a first storage processor in the storage system, the first RAID having a high I/O load at the disk extent level. Then, a first disk extent for reconstructing the first RAID stripe is determined and the first storage processor is configured to reconstruct data for the first RAID stripe at the first disk extent. A corresponding device to implement the method is further disclosed.

Abstract: Techniques coordinate access operations. Such techniques involve: obtaining first statistical data of a first set of access operations associated with a first storage resource pool in the RAID and second statistical data of a second set of access operations associated with a second storage resource pool in the RAID, the first set of access operations including a background access operation and a user access operation, and the second set of access operations including at least a user access operation; determining, based on the first and second statistical data, availability of a memory shared by the first and second storage resource pools; and adjusting, based on the availability, the background access operation in the first set of access operations to control a capacity of the memory occupied by the background access operation. Accordingly, the response time of the storage system for the user access operations can be shortened, etc.

Abstract: A method and device of managing storage array configuration. The method includes storing a basic configuration information of a user drive onto a system drive, storing an extended configuration information of the user drive onto the user drive, and, in response to a change of the storage array, creating a new disk array group or updating a disk array group according to the basic configuration information and the extended configuration information.

Abstract: Embodiments of the present disclosure relate to a method and a device for cache management. The method includes: in response to receiving a write request for a cache logic unit, determining whether a first cache space of a plurality of cache spaces associated with the cache logic unit is locked; in response to the first cache space being locked, obtaining a second cache space from the plurality of cache spaces, the second cache space being different from the first cache space and being in an unlocked state; and performing, in the second cache space, the write request for the cache logic unit.