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: 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: 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: 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: 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 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: 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 involve avoiding a potential failure event on a disk array. Along these lines, data collected for a disk array are obtained. It is determined, based on the collected data, whether a potential failure event is to occur on the disk array. In response to determining that the potential failure event is to occur on the disk array, an action to be taken for the disk array is determined, to avoid occurrence of the potential failure event.

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 storage system comprises at least one stripe, a stripe of the at least one stripe comprising multiple extents among which respective extents being from respective storage devices in a resource pool. The method comprises: in response to receiving a converting request to convert the storage system from a first type to a second type, determining a target storage device associated with the converting request in the resource pool; for a stripe of the at least one stripe, updating metadata associated with the stripe so as to remove from the stripe an extent that is located at the target storage device; and converting the storage system from the first type to the second type on the basis of the updated metadata.

Abstract: Techniques manage a storage system. Along these lines, a failed storage device is detected among storage devices included in a resource pool of the storage system, and the storage devices belong to a first group and a second group in the resource pool respectively. An extent in the failed storage device assigned for building a stripe in the storage system is determined. A spare reserved extent is selected from respective reserved extents included in respective storage devices among the storage devices based on a mapping relation between the stripe and a plurality of extents in the stripe. The respective reserved extents are shared among the first group and the second group. Data in the extent are rebuilt to the selected spare reserved extent. A reserved storage area can be shared among various storage devices in the resource pool, so as to increase allocatable space in storage devices.

Abstract: Techniques for splitting a disk set involve obtaining stripe shared information in a first disk set, wherein the information indicates a stripe set that shares a plurality of disks. The techniques further involve determining the number of disks to be split from the first disk set. The techniques further involve splitting the first disk set into a first portion and a second portion based on the information and the number of disks to be split, wherein the second portion and one or more newly added disks form a second disk set, and both the first disk set and the second disk set store data through Redundant Array of Independent Disks (RAID). In the case that a current disk set needs to be split due to adding one or more new disks, disks are selected using the collected information, thereby reducing data movements caused by splitting of the disk set.

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 method and device for storage management comprising: in response to receiving a request for creating an extent pool, creating the extent pool at least on a user disk, the extent pool comprising a plurality of disk extents; storing data in at least one disk extent of the plurality of disk extents; and storing address information for locating the at least one disk extent in a system disk communicably connected to the user disk. Through the technical solution of the present disclosure, the user can store metadata associated with RAID in the user disk and load metadata associated with RAID from the user disk so as to reduce the access and load of the system disk.

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: A method, computer program product, and computer system for reducing, by a computing device, overlap in a RAID extent group by moving a first disk extent in an extent pool from a source disk to a target disk in a Mapped RAID group. A neighborhood matrix for the Mapped RAID group may be balanced by moving a second disk extent in the extent pool from the source disk to the target disk in the Mapped RAID group.

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 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: The present disclosure provides a storage management method, a device and a computer-readable medium. The method comprises: receiving a request for creating a storage space, the request at least comprising a storage capacity and a RAID configuration of the storage space, the RAID configuration at least indicating a RAID type; allocating an extent based on the storage capacity; creating a RAID group for the extent based on the RAID type; and storing metadata of the RAID group in the extent, the metadata indicating a configuration of the RAID group and a configuration of a user data region in the extent.

Abstract: Implementations of the present disclosure relate to a method and apparatus for handling an error for a drive. The logic space of the drive is divided into a plurality of extents. The method comprises determining a type of errors in response to the errors detected in I/O operations for the drive. The method further comprises determining a drive extent of the plurality of extents of the drive that causes the errors in response to determining that the type of the errors is a soft medium error or a data error, the soft medium error being an error that can be repaired by re-mapping of a failed extent and the data error being an error that is caused by damage of data on the drive. Furthermore, the errors can be handled only with respect to the drive extent that causes the errors.

Abstract: A method of initializing a data storage system (DSS) is provided. The method includes (a) in response to the DSS booting, reading data from a first plurality of disks marked as part of a raw mirror which mirrors configuration data of the DSS between the first plurality of disks; (b) comparing sequence numbers from the read data read and selecting data from a disk of the first plurality having a latest sequence number; (c) obtaining configuration data of the DSS from the selected data; (d) using the configuration data to construct a topology of the DSS which includes information describing a relationship between a second plurality of disks of the DSS, RAID groups of the DSS, and logical disks presented to users, the second plurality of disks being larger than and including the first plurality of disks; and (e) initializing the RAID groups and the logical disks described by the topology based on the information of the topology.