Abstract: Techniques involve dividing a disk in RAID into a plurality of slices, and the plurality of slices include a first slice and a second slice with a first size. The techniques further involve dividing the second slice into a plurality of sub-slices, and each sub-slice in the plurality of sub-slices has a second size smaller than the first size. The techniques further involve forming a first stripe set for storing user data using the first slice and forming a second stripe set for storing metadata using the sub-slices. Such techniques enable configuring a smaller slice size for the set stripe for the metadata, and thus the granularity of storage and migration for the metadata can be reduced, and the metadata can be distributed into more disks in the RAID.

Abstract: Techniques involve: in response to receiving an access request for a logical address, determining a first virtual storage unit and a first offset within the first virtual storage unit corresponding to the logical address; determining a first set of virtual storage units to which the first virtual storage unit belongs and a position of the first virtual storage unit, determining, from the plurality of physical storage units corresponding to the first set of virtual storage units and based on the position and the first offset, a physical storage unit and a second offset within the physical storage unit corresponding to the logical address; and performing, based on an identifier of the physical storage unit and the second offset, a data access operation requested by the access request. Accordingly, I/O loads on a plurality of disks can be balanced, thereby improving overall performance of a storage system.

Abstract: In certain techniques, a plurality of storage devices of a storage system are sorted into a sequence of storage devices by capacity. A first number of at least one storage device with maximum capacity in the sequence of storage devices is determined. A group of storage devices are selected from the sequence of storage devices based on the first number, a device number of storage devices in the sequence and a threshold device number, the number of storage devices in the group of storage devices being less than or equal to the threshold device number. A user storage system is built based on storage space in the group of storage devices, the user storage system having a predetermined width for representing a sum of a data width and a parity width in one stripe of the user storage system. Accordingly, efficiency of storage space utilization can be improved.

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 for mapping large storage extents (“ubers”) into storage drive groups (“resiliency groups”) in a data storage system. The techniques can include, as the capacity of storage drives included in a first resiliency group is used up, forming a second resiliency group with one or more new storage drives. The disclosed techniques can further include allocating one or more storage drives from the first resiliency group to the second resiliency group to satisfy a requirement of a predetermined RAID storage configuration, and performing a reduced number of data movement operations to assure that data slices of one or more ubers initially assigned to the first resiliency group are allocated to storage drives in the same first or second resiliency group. In this way, data storage systems can be made to support a desired storage drive expansion with a reduced number of new storage drives.

Abstract: Techniques manage a storage system. In accordance with certain techniques, respective response times of multiple storage devices associated with the storage system are obtained. An extent whose workload satisfies a predefined condition is selected as a source extent from multiple extents on a source storage device in response to a response time of the source storage device among the multiple storage devices being above a predefined threshold. A destination storage device is selected from the multiple storage devices, the destination storage device having a lower workload than the source storage device. Data on the source extent are moved to a free extent on the destination storage device. Additionally, a balance may be stricken between workloads of various storage devices in a resource pool, and then the overall response speed of the resource pool may be increased.

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 for managing metadata at a control device involve: determining, from a cache page corresponding to user data, a first region for storing raw metadata of the user data, the raw metadata including address information for storing the user data in a storage system; in response to the user data being modified, determining updated metadata of the modified user data to update the raw metadata in the first region; and copying the updated metadata to a high-speed memory shared by the control device and another control device. Accordingly, the techniques are capable of reducing the usage frequency of the high-speed memory, thereby extending the service life of the high-speed memory and reducing cost.

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: 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 provide for data rebuilding in a storage system. The techniques involve: in response to failure of a first disk in the storage system, determining a second disk having a high risk of failure in the storage system; determining whether the second disk contains a second data block that is associated with a first data block to be rebuilt in the first disk, the first and second data blocks being from a same data stripe in the storage system; and in response to determining that the second disk contains the second data block and the second data block has not yet been replicated into a third disk for backup in the storage system, reading the second data block from the second disk to rebuild the first data block, and replicating the read second data block into the third 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: 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: Implementations of the subject matter described herein provide a storage management method and system. The storage management method comprises: in response to receiving a write request, dividing data to be written into a plurality of data blocks with a predetermined size, the plurality of data blocks having their respective logic block addresses; evenly mapping, based on the logic block addresses, the plurality of data blocks to a plurality of RAID extents of a Redundant Array of Independent Disks (RAID); mapping the plurality of data blocks in the plurality of RAID extents to the disk, so that the plurality of data blocks are distributed in order of size of logic block addresses in the disk.

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: 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, one or more drives added to an extent pool of storage devices. An empty Mapped RAID group may be generated. A plurality of extents in the extent pool may be shuffled. A RAID extent may be mapped to the empty Mapped RAID group, wherein the RAID extent is mapped to the empty Mapped RAID group while shuffling the plurality of extents in the extent pool.

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.