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: 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 manage a storage system. The storage system includes at least one part of multiple storage devices, here respective storage devices among the multiple storage devices include a first portion and a second portion, the first portion is for storing data and the second portion is reserved for rebuilding the storage system. The techniques involve: determining a storage device in the at least one part of storage devices fails; recovering data in a first portion of the failed storage device on the basis of data in a first portion of a normal storage device other than the failed storage device in the at least part of storage devices; selecting a group of storage devices from normal storage devices among the multiple storage devices; and writing recovered data to a second portion in the group of selected storage devices. Thereby, the speed of rebuilding the storage system may be increased, and further the overall performance of the storage system may be enhanced.

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: Embodiments of the present disclosure relate to method, device and computer readable storage media for rebuilding redundant array of independent disks (RAID). The method comprises: in response to detecting at least one fault disk in the RAID, adding a new disk to the RAID for rebuilding; determining, according to a mapping table, a first set of storage blocks marked as “free” in the at least one fault disk, the mapping table indicating usage state of storage space in the RAID; and writing a predetermined value into a second set of storage blocks corresponding to the first group of storage blocks in the new disk.

Abstract: Techniques are directed to failure recovery of a storage system. In accordance with certain techniques, in response to detecting that a disk group of a memory system failed, failure duration of the disk group is recorded. If the failure duration does not reach a predetermined ready time limit and the disk group is in a degraded state, the disk group is maintained in a degraded but not ready state. The predetermined ready time limit is shorter than a logic unit number debounce time limit to avoid a data unavailable event. With such techniques, the possibility of occurrence of a data loss event may be reduced significantly while avoiding a data unavailable event.

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.

Abstract: Implementations of the present disclosure relate to a method, system and computer program product for managing a storage system. Specifically, in one implementation of the present disclosure there is provided a method for managing a storage system. The method comprises: dividing a source device among a plurality of storage devices in the storage system into a plurality of extents; copying data in the plurality of extents to a destination device; determining the state of an extent among the plurality of extents on the basis whether data in the extent among the plurality of extents has been copied to the destination device; and managing an access request to the extent on the basis of the state of the extent. In other implementations of the present disclosure, there is provided a corresponding system and computer program product.

Abstract: A method, computer program product, and computer system for receiving, by a computing device, an I/O request for data. A number of storage devices of a plurality of storage devices in a Mapped RAID group that will be used to process the I/O request may be determined. It may be determined that each storage device of the number of storage devices in the Mapped RAID group that will be used to process the I/O request lacks a respective threshold number of credits to process the I/O request. It may be determined whether a cache associated with the Mapped RAID group allows a user I/O queue. If the cache allows the user I/O queue, a user I/O may be placed in the user I/O queue. If the cache does not allow the user I/O queue, the I/O request may be failed.

Abstract: Embodiments of the present disclosure relate to a method for managing a storage system, an electronic device, a storage system and a computer program product. The method includes: expanding a second number of existing disks with a first number of expanded disks to rebuild a redundant array of independent disks (RAID) having a predetermined extent width, the RAID being built based on the existing disks, and the predetermined extent width indicating a number of disk extents from different disks that form an RAID extent. The method further includes: determining a third number of RAID extents contained in the rebuilt RAID. The method further includes: determining a count of data movements to be performed between the expanding disks and the existing disks during the rebuilding based on the first number, the second number, the third number and the predetermined extent width. With this method, time for estimating count of data movements may be reduced.

Abstract: The techniques involve, in response to receiving a message indicating that a failure occurs in a first disk group of an array, selecting, from lists in a cache, a first entry to be written into the array, the lists including first and second lists, wherein the first list is used to cache a data entry for the first disk group. The techniques further involve, in response to determining that the first entry comes from the first list, writing the first entry into the array; in response to determining that the first entry comes from the second list and the first entry is to be written into the first disk group, moving the first entry from the second list to the first list; and in response to determining that the first entry is to be written into the second disk group, writing the first entry into the second disk group.

Abstract: Techniques manage a disk array. Such techniques involve determining, from one or more disk arrays constructed based on a plurality of disks, a target disk array to be restriped, the target disk array being associated with disk slices on different disks and including a stripe to be reconstructed, the stripe including extents located in the disk slices; determining, from the disk slices, a first disk slice on which data migration is to be performed, a first extent of the extents being located in the first disk slice; allocating, on the plurality of disks, a second disk slice for storing data from the first disk slice; and reconstructing the stripe by migrating data from the first extent of the first disk slice into the second disk slice. Such techniques significantly reduce the number of input/output operations during stripe reconstruction while avoiding waste of storage space.

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 for managing data involve receiving a write request to write a data block into a first stripe in a disk array, the write request comprising a first storage address for storing the data block. The techniques further involve determining, based on the first storage address, a first group of disks related to a data portion of the first stripe and a second group of disks related to a parity portion of the first stripe. The techniques further involve, in response to a first disk in the first group of disks being unavailable, storing a data sub-block related to the first disk into a first parity portion of the parity portion such that the data block is stored in the first stripe, the first parity portion being located at a second disk in the second group of disks. The techniques further involve returning a response to the write request, the response comprising a first indication indicating a status of the disks in the disk array.

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: Storage management techniques involve determining a set of association degrees associated with a set of storage disks, the set of storage disks forming a set of Redundant Arrays of Independent Disks (RAIDs), and an association degree of the set of association degrees indicating a coupling degree of a pair of storage disks in the set of storage disks, the coupling degree being determined based on a number of RAIDs associated with the pair of storage disks. Such techniques further involve determining a first number of pairs of storage disks, wherein the coupling degree of each pair of storage disks is less than a predetermined coupling threshold; and in response to determining that a ratio of the first number to a total number of pairs of storage disks of the set of storage disks is greater than a predetermined ratio threshold, reorganizing at least one RAID in the set of RAIDs.

Abstract: Techniques perform data access to a disk array. The disk array includes a parity disk and a plurality of data disks. Via such techniques, data is written to the parity disk in the disk array in response to a write request to a failed data disk in the disk array when the disk array is in a degraded state; and corresponding degraded storage position information is set in disk resource mapping information so as to indicate that the data are stored in the parity disk. Accordingly, enormous computing resources can be saved, and I/O operations required by reads in the degraded state can be reduced.

Abstract: A method and a manager for managing a storage system including a manager and a storage device. The storage device includes a data region and a metadata region. The data region is divided into data blocks. The metadata region stores metadata describing zeroing states of the data blocks. The method comprises allocating a metadata cache in a memory of the manager. The metadata cache includes respective zeroing indication bits indicative of the zeroing states of the corresponding data blocks. The allocating procedure comprises allocating a user data cache for reading or writing user data and allocating a background zeroing cache for a background zeroing operation of the storage device. The method further comprises, in response to receiving an I/O request for the storage system, processing the I/O request with the metadata cache.

Abstract: Implementations of the present disclosure relate to a method, system and computer program product for managing a storage system. Specifically, in one implementation of the present disclosure there is provided a method for managing a storage system. The method comprises: determining an access level of a target extent comprised in a stripe of a storage system, the access level indicating the possibility that the target extent will be accessed; obtaining a usage state of a target storage device where the target extent resides, the target storage device residing in a storage device pool associated with the storage system; and processing a mapping relationship between the target extent and the target storage device on the basis of the access level and the usage state. In other implementations of the present disclosure, there is provided a corresponding system and computer program product.

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.