Abstract: Technology for determining an effective capacity of a drive extent pool that is generated from at least one group of storage drives. A sub-group of storage drives having relatively higher physical capacities is selected from the group. The number of storage drives in the sub-group is equal to a total number of drive extents indicated by each entry in a RAID mapping table. Each storage drive in the sub-group is assigned an individual effective capacity equal to an individual physical capacity of a storage drive in the sub-group having the smallest individual physical capacity. Each storage drive in the group not contained in the sub-group is assigned an individual effective capacity equal to its own physical capacity. An effective capacity of the drive extent pool is set to a sum of the all the individual effective capacities assigned to the storage drives in the group of storage drives.

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: 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: 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 thus realized.

Abstract: Techniques perform I/O management. The techniques involve: in response to receiving an I/O request for a redundant array of independent disks (RAID), determining a stripe of the RAID related to the I/O request; determining metadata corresponding to the stripe, the metadata indicating validity of current data in a corresponding data block of the RAID, the data block comprising one or more stripes; in response to the metadata indicating that the current data is valid, executing the I/O request by accessing the RAID; and in response to the metadata indicating that the current data is invalid, responding to the I/O request with zero data as the current data. Accordingly, disk access is reduced, metadata cache efficiency is increased, I/O performance is improved and the RAID reliability is enhanced.

Abstract: Techniques manage a cache. Such techniques involve creating a primary cache by a cache management module in a storage system. Such techniques further involve: in response to the primary cache being created, sending a first request to a hardware management module to obtain first information about a first virtual disk. Such techniques further involve: in response to receiving the first information from the hardware management module, creating a secondary cache using the first virtual disk. Such techniques further involve: in response to an available capacity of the primary cache being below a predetermined threshold, flushing at least one cache page in the primary cache to the secondary cache. In certain techniques, it is possible to use spare extents in the disk array to create the secondary cache to increase a total capacity of the cache in the system, thereby improving the access performance of the system.

Abstract: Techniques manage a storage system. In accordance with such techniques, an access request for target data is received; a storage position of the target data is determined, the storage position indicating one of a storage device and a cache; a target element corresponding to the target data is determined from a first replacement list and a second replacement list associated with the first replacement list based on the storage position, the first replacement list including at least a counting element, the counting element indicating an access count of data in the storage device, the second replacement list including a low-frequency access element, the low-frequency access element indicating a cache page with a low access frequency in the cache; and a position of the target element in a replacement list where the target element exist is updated. Therefore, the overall performance of the storage system can be improved.

Abstract: Techniques manage redundant arrays of independent drives (RAID). The techniques involve: in response to a target stripe to be built in the RAID, determining, from a resource pool, whether there are spare extents associated with at least one system disk. The techniques further involve: in response to determining that there are spare extents associated with at least one system disk, determining an adjacent relationship of used extents associated with the at least one system disk within a RAID stripe. The techniques further involve: determining, based on the adjacent relationship and the spare extents, an extent for building the target stripe. Accordingly, the total number of the RAID stripes including extents associated with the system disks can be reduced significantly, and a balance can be achieved within spare extents associated with system disks and spare extents associated with user disks for building a RAID stripe.

Abstract: A method, computer program product, and computer system for initializing, on a computing device, an N*N Weighted Neighborhood Matrix according to an existing Mapped RAID layout. N disks in an original disk partner group (DPG) may be partitioned into a target DPG, where N is a number of disks in an extent pool, wherein the N disks have at least two different capacities. The target DPG may be marked for at least a portion of the N disks. The target DPG may be marked for E RAID extents, where E is a number of RAID extents in the original DPG. At least a portion of disk extents for the E RAID extents in the original DPG may be moved to the target DPG.

Abstract: a method and an apparatus for maintaining reliability of a mapped redundant array of independent disks. The method comprises: determining a first data loss probability, the first data loss probability indicating reliability of a traditional redundant array of independent disks; determining a second data loss probability, the second data loss probability indicating reliability of the mapped redundant array of independent disks; and determining, based on the first and second data loss probabilities, a condition for maintaining the reliability of the mapped redundant array of independent disks. Compared with the prior art, embodiments of the present disclosure can effectively predict the reliability of a mapped RAID through comparison with a traditional RAID, so as to be capable of determining a reliability relationship between the traditional RAID and the mapped RAID. In this way, the reliability of the traditional RAID will not be degraded when being expanded into the mapped RAID.

Abstract: A method, computer program product, and computer system for selecting, by a computing device, a first disk extent for each RAID extent in an extent pool. Remaining disk extents for each RAID extent in the extent pool may be selected.

Abstract: A method includes in response to receiving an I/O request for the storage system, determining information associated with the I/O request; generating a timestamp associated with the I/O request; and recording the information and the timestamp to reproduce an operation associated with the I/O request. A method comprises: in response to a request for reproducing an I/O operation of the storage system, obtaining information associated with at least one I/O request for the storage system, the information being recorded in response to reception of the at least one I/O request; obtaining at least one timestamp corresponding to the at least one I/O request; and reproducing the operation of the at least one I/O request on the storage system based on the information and the at least one timestamp.

Abstract: A storage method and device for a solid-state drive is provided in embodiments of the present disclosure. The method includes: configuring a checkpoint drive and a cache drive; backing up data blocks from a data drive into the checkpoint drive; and in response to the data drives being corrupted, writing into a further data drive part of the data blocks backed up into the checkpoint drive and part of data blocks in the cache drive. The number of required SSD drives can be significantly reduced with the method and device without losing the data restoration capability. In addition, the degrading performance can also be maintained at a relatively high level.

Abstract: Embodiments of the present disclosure provide a method and device for storage management. The method comprises receiving at a storage management device a configuration request for a storage space managed by the storage management device, the configuration request indicating a capacity of the storage space and a target size of a chunk in the storage space; and based on the capacity and the target size, dividing the storage space into a metadata region storing a chunk status indicator indicating whether the chunk is assigned with data and a data region including the chunk with the target size. Embodiments of the present disclosure also provide a corresponding device.

Abstract: Embodiments of the present disclosure relate to a method and apparatus for rebuilding redundant array of independent disks (RAID). The method comprises dividing a RAID group including a disk into a plurality of stripes in response to detecting a failure of the disk, and each stripe includes a disk slice across all disks of the RAID group. The method further comprises mapping the plurality of stripes to other RAID groups respectively and rebuilding data on the plurality of stripes in other RAID groups. Embodiments of the present disclosure rebuild in parallel the stripes of the failed RAID group in other RAID groups, thereby effectively increasing the rebuilding speed for RAID and ensuring reliability of the RAID group.

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: Techniques involve: in response to a number of errors of an error type in a storage disk increasing, determining an adjustment rate for a health value of the storage disk based on a total usage time length of the storage disk, where a longer total usage time length corresponds to a higher adjustment rate, and the health value indicates a health condition of the storage disk with respect to the error type. The techniques further involve increasing the adjustment rate based on a total input/output (I/O) number of the storage disk, where a greater total number of I/Os corresponds to a greater increment. The techniques further involve adjusting the health value with the adjustment rate. Such techniques can improve the accuracy of evaluating the health condition of the storage disk.

Abstract: While migrating a source volume to a destination storage array, disabling the source volume causes a source storage array to send a non-standard failure status code to all host computers in a cluster that includes the source storage array and the destination storage array. While the source volume is disabled with regard to standard host I/O requests received from host computers in the cluster, in response to receipt of the non-standard failure status code, a customized plugin added to the host computers transfers persistent reservation information to the destination storage array using non-standard read and set persistent reservation information commands. The destination volume is then enabled to process host I/O requests in accordance with the transferred persistent reservation information, and an active path for accessing the source volume is modified in each one of the host computers in the cluster to indicate the destination volume in the destination storage array.

Abstract: Various techniques are directed to a storage management method, an electronic device and a computer readable medium. Such techniques may involve: receiving a request for a target storage block in a disk; obtaining, from a cache, a cache indicator indicating a state of a group of storage blocks including the target storage block, the number of bits occupied by the cache indicator in the cache being less than the number of storage blocks in the group of storage blocks; and responding to the request based on the cache indicator. Such techniques can reduce times of access to the disk and thereby enhancing input/output performance.

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.