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: 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: 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: 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 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: Techniques for managing storage devices involve: combining storage devices in a redundant array of independent disks (RAID) into a group of devices in an order of physical storage capacities; determining a first number of device sets based on a number of devices in the group and a threshold number of devices to be divided into each set, the number of the devices being greater than the threshold number; selecting at least one capacity promotion set from the group, each capacity promotion set including a second number of devices having a same physical capacity, the second number being equal to a sum of a width of the RAID and a number of devices in each set that is reserved; and forming the first number of sets by combining each of capacity promotion set and devices in the group other than each capacity promotion set.

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: Techniques provide for managing storage devices. Such techniques involve: combining storage devices in a redundant array of independent disks into a group of storage devices in an order of physical capacities of the storage devices; determining a first number of sets of storage devices based on a number of storage devices in the group and a threshold number of storage devices to be divided into each of the sets; and dividing, based on a configuration of the redundant array of independent disks, the group of storage devices into the first number of sets of storage devices, to optimize an effective capacity of the redundant array of independent disks.

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: 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: 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, 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: The present disclosure relates to a method and device for managing a storage system. Specifically, in one implementation of the present disclosure, there is proposed a method for managing a storage system. The method comprises: obtaining a state record on utilization of a resource pool for creating the storage system, the resource pool comprising a first number of storage devices, the state record comprising a time sequence in which extents in the first number of storage devices are selected to create the storage system; selecting extents from the first number of storage devices to create the storage system according to the state record; and updating the state record on the basis of the selected extents. In one implementation of the present disclosure, there is proposed a device for managing a storage system.

Abstract: Embodiments of the present invention provide a method and system for managing a storage area. In one embodiment of the present invention, there is provided a method for managing a storage areas, comprising: obtaining a storage area in a storage system according to a predefined dividing rule; determining status regarding whether the storage area has been used; setting a status identifier for the storage area based on the use status; and managing the storage area based on the status identifier. In another embodiment, there is proposed a system for managing a storage area, comprising: one or more processors; a memory coupled to at least one processor of the one or more processors; computer program instructions stored in the memory which, when executed by the at least one processor, cause the system to execute a method for managing a storage area.

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: Embodiments of the present disclosure generally relate to a method and device for managing caches. In particular, the method may include in response to receiving a request to write data to the cache, determining the amount of data to be written. The method may further include in response to the amount of the data exceeding a threshold amount, skipping writing data to the cache and writing the data to a lower level storage of the cache. Corresponding systems, apparatus and computer program products are also provided.

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: In a method and apparatus for storage management, a method includes: creating a plurality of profiles for address mapping, the profiles comprising a part of mapping relation in the total mapping table and creating an index for a part of the plurality of profiles to accelerate the lookup speed. A corresponding device and computer program product are also disclosed.

Abstract: A method and system for managing a buffer device in a storage system. The method comprising determining a first priority for a first queue included in the buffer device, the first queue comprising at least one data page associated with a first storage device in the storage system; in at least one round, in response to the first priority not satisfying a first predetermined condition, updating the first priority according to a first updating rule, the first updating rule making the updated first priority much closer to the first predetermined condition than the first priority; and in response to the first priority satisfying the first predetermined condition, flushing data in a data page in the first queue to the first storage device.

Abstract: Embodiments of the present disclosure relate to a method, device and computer program product for managing a disk array. The method comprises determining respective degrees of wear for a plurality of disks in the disk array, each of the plurality of disks comprising a plurality of disk extents, and each disk extent comprising a plurality of blocks. The method further comprises determining respective numbers of blocks that are accumulatively written into the plurality of disks during a predetermined period of time. The method further comprises migrating data among the plurality of disks based on the degrees of wear and the number of the accumulatively written blocks.