Abstract: Techniques for allocating storage space of disks in a storage system involve selecting a current storage node from a plurality of storage nodes according to at least one previously selected storage node and association relationships between the plurality of storage nodes. Such techniques further involve selecting a current disk from a plurality of disks according to at least one previously selected disk, the current storage node, and association relationships between the plurality of disks. Such techniques further involve allocating at least one slice in the current disk to a redundant array of independent disks (RAID) stripe. Such a technique can support a distributed storage system having more storage nodes, can greatly reduce the time for allocating the storage space of disks, and can make a RAID stripe evenly allocated between the storage nodes and the disks in the storage system, thereby greatly improving a success rate of data recovery.

Abstract: Techniques for storage management involve determining, based at least on an upper limit duration for recovering a predetermined number of disk sets among a plurality of disk sets, a first recovery rate for recovering at least a portion of the plurality of disk sets. The techniques may further involve determining the number of disk sets that are not recovered based on the first recovery rate among the plurality of disk sets. In addition, the techniques may further involve performing data recovery on unrecovered disk sets among the plurality of disk sets based on a predetermined second recovery rate according to the determined number being less than or equal to the predetermined number, the second recovery rate being lower than the first recovery rate and being associated with the upper limit duration. Accordingly, it can be ensured that all to-be-recovered disk sets may be recovered within a recovery duration.

Abstract: Techniques involve: determining a first group of storage disks, a use rate of each storage disk of the first group of storage disks exceeding a first threshold, the first group of storage disks comprising a first group of storage blocks corresponding to a first redundant array of independent storage disk (RAID); allocating a second group of storage blocks corresponding to a second RAID from a second group of storage disks, the second group of storage blocks having the same size as that of the first group of storage blocks, a use rate of each storage disk of the second group of storage disks being under a second threshold; moving data in the first group of storage blocks to the second group of storage blocks; and releasing the first group of storage blocks from the first group of storage disks. Thus, use rates of the storage disks become more balanced.

Abstract: In response to receiving a read request for target data, an external address of the target data is obtained from the read request, which is an address unmapped to a storage system; hit information of the target data in cache of the storage system is determined based on the external address; and based on the hit information, an address from the external address and an internal address for providing the target data is determined. The internal address is determined based on the external address and a mapping relationship. Therefore, it can shorten the data access path, accelerate the responding speed for the data access request, and allow the cache to prefetch the data more efficiently.

Abstract: A storage management technique involves: selecting a first disk from a plurality of disks in a storage system as an anchor disk; allocating a first backup slice from the plurality of disks to a redundant array of independent disks (RAID) associated with the first disk, the first RAID including at least a slice allocated from the first disk; and if it is detected that there is an inaccessible disk in the plurality of disks, determining a backup slice for a slice of the inaccessible disk based on the allocation of the first backup slice to the first RAID, for use in data reconstruction of the inaccessible disk. This can ensure that a backup slice can always be successfully determined for slices of an inaccessible disk without introducing additional time complexity.

Abstract: Techniques provide for managing data storage. The techniques involve in response to receiving a request for unmapping a logical storage unit associated with a first disk slice on a first physical disk and the first disk slice, determining information associated with the first disk slice; generating, based on the information, a first entry and a second entry corresponding to the first disk slice; adding the first entry into a queue of failed disk slices to enable data stored on the first disk slice to be cleared; and adding the second entry into a queue of free disk slices to enable the first disk slice to be mapped to a further logical storage unit. Accordingly, such techniques can remarkably improve the write I/O performance of the system and prolong the lifetime of the SSD.

Abstract: In techniques for selecting a rebuild destination in a storage system, a failed stripe group associated with a failed extent group in a failed storage device among storage devices is detected. A group of normal storage devices other than the failed storage device is determined. Regarding a normal storage device in the group of normal storage devices, a first count for the normal storage device is obtained, the first count representing a number of failed stripes which are allowed to be rebuilt to the normal storage device in the failed stripe group. Based on the first count, a destination storage device is selected from the group of normal storage devices for rebuilding a failed stripe in the failed stripe group. During rebuild, a destination for rebuilding the failed stripe may be effectively selected, and extents in reserved space in the storage system may be more fully utilized.

Abstract: Techniques involve: determining, according to a determination that a performance level of a target storage unit is lower than a threshold level, whether idle disk slices that can be used for reconstructing malfunctioning disk slices in the target storage unit exist in a slice pool; determining a priority of the target storage unit according to a determination that the idle disk slices do not exist; and selecting replacing disk slices for reconstructing the malfunctioning disk slices from available storage units based at least in part on the priority, wherein the available storage units have performance levels not lower than the threshold level. In this way, data loss due to the off-line of storage units is prevented; and meanwhile, the performance of the entire storage system can be globally stabilized.

Abstract: Techniques for storage management may include: adding first storage devices to a pool, wherein prior to adding the first storage devices to the pool, the pool includes second storage devices with existing physical storage units (PUs) distributed across the second storage devices; and in response to adding the first storage devices to the pool, performing processing to evenly distribute the existing PUs among the pool of storage devices, said processing including: defining logical pairs of storage devices in accordance with rules; binding each of the logical pairs to a resiliency set; determining that a first PU of the existing PUs includes disk slices that span across more than a single resiliency set; andin response to determining that the first PU includes disk slices that span across more than a single resiliency set, performing second processing to restripe the first PU in accordance with a target layout.

Abstract: Techniques for storage management may include: adding first storage devices to a pool, wherein prior to adding the first storage devices to the pool, the pool includes second storage devices with existing physical storage units (PUs) distributed across the second storage devices; and in response to adding the first storage devices to the pool, performing processing to evenly distribute the existing PUs among the pool of storage devices, said processing including: defining logical pairs of storage devices in accordance with rules; binding each of the logical pairs to a resiliency set; determining that a first PU of the existing PUs includes disk slices that span across more than a single resiliency set; and in response to determining that the first PU includes disk slices that span across more than a single resiliency set, performing second processing to restripe the first PU in accordance with a target layout.

Abstract: Techniques for storage management involve: in response to a first disk becoming offline and remaining offline until a first time point, selecting a second storage slice in a second disk as a backup storage slice for a first storage slice in the first disk, the first storage slice being one of slices forming a redundant array of independent disks (RAID), the slices being located in different disks. The techniques further involve: writing, between the first time point and a second time point, data to be written into the first storage slice in the RAID to the second storage slice, the second time point being later than the first time point. The techniques further involve: in response to the first disk remaining offline until the second time point, replacing the first storage slice in the RAID with the second storage slice. Such techniques may improve performance of a RAID-based storage system.

Abstract: Techniques involve: determining a source disk slice from a plurality of disk slices of a plurality of storage arrays providing redundant storage, target data on the source disk slice needing to be removed; determining a destination disk slice for storing the target data needing to be removed from the source disk slice, a destination disk where the destination disk slice is located being different from a source disk where the source disk slice is located; and moving the target data from the source disk slice to the destination disk slice. Accordingly, such techniques can improve efficiency of a storage system.

Abstract: Techniques involve managing a storage system. In accordance with the techniques, a plurality of copies of metadata of the storage system are read from a plurality of storage devices in a resource pool of the storage system. The resource pool includes a first number of storage devices, and the metadata describes configuration information of the storage system. A second number of copies are selected from the plurality of copies based on version information in the plurality of copies, where the second number of copies comprises the metadata in the same version. It is determined whether a relation between the first number and the second number satisfies a predetermined condition. The second number of copies are identified as trusted metadata based on determining the relation satisfies the predetermined condition. With the foregoing example implementation, the metadata in the storage system may be managed with higher reliability.

Abstract: Techniques for storage management involve determining, based at least on an upper limit duration for recovering a predetermined number of disk sets among a plurality of disk sets, a first recovery rate for recovering at least a portion of the plurality of disk sets. The techniques may further involve determining the number of disk sets that are not recovered based on the first recovery rate among the plurality of disk sets. In addition, the techniques may further involve performing data recovery on unrecovered disk sets among the plurality of disk sets based on a predetermined second recovery rate according to the determined number being less than or equal to the predetermined number, the second recovery rate being lower than the first recovery rate and being associated with the upper limit duration. Accordingly, it can be ensured that all to-be-recovered disk sets may be recovered within a recovery duration.

Abstract: A technique for managing storage units involves: if it is determined that a first metadata storage unit for storing metadata of a plurality of storage units fails, allocating a second metadata storage unit for replacing the first metadata storage unit from a storage resource pool, wherein the metadata is read into a memory before the failure occurs, and first metadata of the first metadata storage unit is recorded in configuration information for indicating a valid metadata storage unit; recording second metadata of the second metadata storage unit in the configuration information; storing the metadata in the memory into the second metadata storage unit; and replacing the first metadata storage unit with the second metadata storage unit by validating the second metadata and invalidating the first metadata in the configuration information. Accordingly, such a technique improves reliability of a metadata storage unit.

Abstract: Techniques for rebuilding a disk array involve, in response to receiving a message for rebuilding disk arrays in a storage system, determining a target disk that causes rebuilding. Such techniques further involve determining from the disk arrays a set of disk arrays related to the target disk, and generating subsets of disk arrays from the set of disk arrays, each subset including disk arrays that can be rebuilt in parallel. Such techniques further involve determining, based on a number of disks included in each subset, a target subset from the plurality of subsets, and rebuilding disk arrays in the target subset in parallel. Accordingly, a disk array that is most suitable for parallel rebuilding may be determined, and the process of rebuilding the disk array is sped up. Such techniques reduce the delay caused by performing rebuilding, and improve rebuilding efficiency.

Abstract: Techniques involve: determining, according to a received request for creating a stripe in a storage system, a type of the stripe; acquiring a first workload distribution corresponding to the determined type, wherein the first workload distribution describes the distribution, among a first number of storage devices, of multiple extents in a set of stripes of this type in the storage system; selecting a set of extents from the first number of storage devices based on the first workload distribution, so that the distribution, among the first number of storage devices, of the selected set of extents and the multiple extents in the set of stripes of this type satisfies a preset distribution condition associated with the type; and using the selected set of extents to create the requested stripe based on a stripe creation rule associated with the type. The stripes can be managed in a more effective manner.

Abstract: A storage management technique involves: selecting a first disk from a plurality of disks in a storage system as an anchor disk; allocating a first backup slice from the plurality of disks to a redundant array of independent disks (RAID) associated with the first disk, the first RAID including at least a slice allocated from the first disk; and if it is detected that there is an inaccessible disk in the plurality of disks, determining a backup slice for a slice of the inaccessible disk based on the allocation of the first backup slice to the first RAID, for use in data reconstruction of the inaccessible disk. This can ensure that a backup slice can always be successfully determined for slices of an inaccessible disk without introducing additional time complexity.

Abstract: A storage management technique involves: receiving from a requesting node a write request for writing target data into a first target storage space in a redundant array of independent disks (RAID); if a storage device associated with the first target storage space does not fail, acquiring first data stored in the first target storage space and a first parity value corresponding to the requesting node and stored in a parity storage space; determining a target parity value based on the target data, the first data, and the first parity value; and updating a stripe with the target data and the target parity value. Accordingly, locks caused by updating the parity value can be avoided, so that different nodes can perform parallel write to different storage spaces in the same stripe in the RAID.

Abstract: A storage management technique involves: receiving from a requesting node a write request for writing target data into a first target storage space in a redundant array of independent disks (RAID); if a storage device associated with the first target storage space does not fail, acquiring first data stored in the first target storage space and a first parity value corresponding to the requesting node and stored in a parity storage space; determining a target parity value based on the target data, the first data, and the first parity value; and updating a stripe with the target data and the target parity value. Accordingly, locks caused by updating the parity value can be avoided, so that different nodes can perform parallel write to different storage spaces in the same stripe in the RAID.