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), placing the I/O request in a corresponding waiting queue based on a stripe related to the I/O request in the RAID; and in response to the I/O request being granted to process, executing the I/O request based on storage of data of the stripe in a cache memory. Accordingly, by using the cache mechanism for the stripes, the I/O processing efficiency is improved and the user experience is enhanced. Moreover, the count of access to the RAID is reduced, the bandwidth for the backend access is saved and the system performance is improved.

Abstract: Techniques manage a storage system and involve: determining priorities of a first set of to-be-executed operations of a first stripe of a plurality of stripes of the storage system and priorities of a second set of to-be-executed operations of a second stripe, the plurality of stripes at least including the first stripe and the second stripe different from the first stripe, and each of the plurality of stripes including a plurality of extents distributed on different storage devices; determining a first to-be-executed operation with the highest priority among the priorities of the first set of to-be-executed operations; determining a second to-be-executed operation with the highest priority among the priorities of the second set of to-be-executed operations; and determining operation execution priorities of the first and second stripes based on the priorities of the first and second to-be-executed operations. Accordingly, the processing performance of the storage system is increased.

Abstract: Mapped RAID (Redundant Array of Independent Disks) technology divides individual drives into multiple drive extents, allocates the drive extents to RAID extent entries in a RAID mapping table, and performs “end of life” detection and proactive copying of data between data storage drives on a per drive extent basis. A given drive extent is determined to be “end of life” when the ratio of soft media errors to total I/O operations for the drive extent exceeds a threshold error ratio. Data stored on the drive extent is then proactively copied to a newly allocated drive extent, the RAID mapping table is modified so that the data is subsequently accessed from the newly allocated drive extent, and the drive extent is excluded from being used again to store host data. As a result, the rate at which the drives experience soft media errors is slowed, lengthening their effective life.

Abstract: Embodiments of the present disclosure provide a solution of evaluating a rebuilding performance of a redundant array of independent disks. In some embodiments, there is provided a computer-implemented method, comprising: simulating, based on a first group of redundant arrays of independent disks, a rebuilding process for a second group of redundant arrays of independent disks; obtaining a first performance metric of the simulated rebuilding process; and identifying a factor associated with the rebuilding performance of the second group of redundant arrays of independent disks based on the first performance metric.

Abstract: Embodiments of the present disclosure provide methods and apparatuses for ensuring data consistency. In some embodiments, a method comprises writing data into a first temporary buffer in a first processor. The method further comprises, in response to the data being written into the first temporary buffer, sending the data to a second processor to update a copy of the data in the second processor. In addition, the method comprises, in response to receiving an indication that the second processor has received the data, copying the data from the first temporary buffer to a first working buffer in the first processor.

Abstract: Embodiments of the present disclosure relate to method and apparatus for scaling out storage devices, and scaled-out storage devices by establishing a cross-device link between a first storage device and a second storage device; exchanging configuration information of at least one of the first storage device and the second storage via the cross-device link; creating, in the first storage device, a shadow object corresponding to a real object in the second storage device; and creating, in the second storage device, a shadow object corresponding to a real object in the first storage device; wherein each shadow object can expose feature and/or state of a corresponding real object to users without implementing a functioning logic of the corresponding real object.

Abstract: A method and device for selecting a Redundant Array of Independent Disks (RAID) level for mapped RAID. The method comprises determining, for a given RAID level, a desired ratio of rebuilding speed between the mapped RAID and non-mapped RAID based on the first number of disks in the non-mapped RAID and the second number of disks in the mapped RAID. The method also comprises determining an actual ratio of rebuilding speed between the mapped RAID and the non-mapped RAID based on the second number of disks in the mapped RAID. In addition, the method comprises selecting the given RAID level for the mapped. RAID in response to the actual ratio being above the desired ratio.

Abstract: A system and method of recognizing a hard disk movement, the system and method including recognizing hard disk information recorded in a hard disk in response to the hard disk being moved to a slot in a hard disk array, determining the movement type of the hard disk based on the recognized hard disk information, judging validity of the hard disk movement based on the movement type, and updating the hard disk information of the hard disk in response to the hard disk movement being judged as valid, wherein the hard disk information comprises position information of the hard disk in the hard disk array.

Abstract: Embodiments of the present disclosure provide a method and a device of managing storage array configuration by 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: 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 apparatus for classifying a failure. The method comprises obtaining a log associated with a failure and identifying a key event in the log, and the key event indicates a predetermined situation. The method further comprises determining a similarity between the failure and each of a set of historical failures based on the key event, and the set of historical failures have been classified into at least one category. The method further comprises classifying the failure based at least partly on the similarity. Embodiments of the present disclosure enable classifying the failure fast and accurately by determining the similarity associated with key event between failures.

Abstract: Embodiments of the present disclosure provide a method and device for storage management. For example, there is proposed a method comprising: in response to a plurality of storage devices in a storage system being to be allocated to an unallocated logic storage area, determining a plurality of allocation schemes for allocating the plurality of storage devices to the unallocated logic storage area; obtaining allocation uniformity of the plurality of storage devices with respect to an allocated logic storage area of the storage system; and selecting one of the plurality of allocation schemes at least based on the allocation uniformity, such that the uniform degree of the allocation has a minimum variation. Corresponding device and computer program product are also disclosed.

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: Embodiments of the present disclosure provide methods and apparatuses for ensuring data consistency. In some embodiments, a method comprises writing data into a first temporary buffer in a first processor. The method further comprises, in response to the data being written into the first temporary buffer, sending the data to a second processor to update a copy of the data in the second processor. In addition, the method comprises, in response to receiving an indication that the second processor has received the data, copying the data from the first temporary buffer to a first working buffer in the first processor.

Abstract: Embodiments of the present disclosure provide a method of storage allocation, an electronic device, a storage system and a computer program product. The method of storage allocation includes: obtaining respective wear levels of a plurality of disks associated with a redundant array of independent disks (RAID). The method further includes: determining respective spare extents in disk extents of the plurality of disks based on the obtained wear levels, such that a number of spare extents in a disk is positively correlated with the wear level of the disk. The method also includes: selecting, from disk extents other than the spare extents, a predetermined number of disk extents for creating RAID extents for the RAID, the predetermined number of disk extents being from different disks of the plurality of disks. Through the embodiments of the present disclosure, a life cycle of a disk is prolonged, frequent replacement of worn disks with new disks is avoided, and data loss is reduced.

Abstract: Techniques change a type of a storage system. The techniques involve: determining, from a resource pool associated with the storage system, a set of used disks utilized by one stripe of the storage system and a set of spare disks unutilized by the stripe; determining a neighboring relationship between spare disks in the set of spare disks and used disks in the set of used disks, the neighboring relationship indicating a number of adjacencies between the spare disks and the used disks in a period of history time; selecting, based on the neighboring relationship, one spare disk from the set of spare disks as an expanded disk of the stripe; and updating the stripe of the storage system using extents of the expanded disk. Accordingly, the type of the storage system may be changed based on the existing resources to improve reliability and operating efficiency.

Abstract: Techniques involve receiving a write request for a first storage block in a source storage area during copying first data from the source storage area to a target storage area. The techniques further involve writing second data associated with the write request into a second storage block of the target storage area, wherein the second storage block corresponds to the first storage block. The techniques further involve updating an indicator associated with the first storage block, wherein the indicator indicates that the second data is written by the write request during the copying. Such techniques enable the data to be written into the target storage area directly without being written into the source storage area by setting an indicator indicating whether a storage block receives a write request during data copying. Accordingly, such techniques can improve write performance during data copying, and extend source storage area lifetime.

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: 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: Techniques manage a storage system. The techniques involve: in response to determining that a rebalance operation is to be performed, determining a source storage device and a destination storage device associated with the rebalance operation based on distribution information of segments included in stripes of the storage system across a plurality of storage devices in the storage system. The techniques further involve: determining a target segment from the source storage device, based on access information of segments in the source storage device. The techniques further involve: moving the target segment to the destination storage device. Accordingly, the rebalance operation can be performed more efficiently, and the overall performance of the storage system can be optimized.