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 are used for improving performance of a storage system. The techniques may be used to provide, among other things, a set of counters for an object. Each counter corresponds to a unique processor in a multi-processor storage system. The state of a gate governing the object is determined. If the state of the gate is open, the counter corresponding to the first processor is incremented. The state of the gate for the object is re-determined. If the state of the gate remains open, the object is read and the counter corresponding to the first storage processor is decremented.

Abstract: A technique involves: in response to receiving a request to write data to a storage device, acquiring metadata of a redundant array of independent disks (RAID) extent that is associated with the request to write data, the RAID extent being built based on disk slices comprised in a plurality of disks of the storage device; determining, based on the metadata, a disk slice of data write-enabled RAID extent to write the data; and copying an identification and a degradation number into a metadata page associated with a mapper for data recovery, the identification and degradation number being comprised in the metadata and associated with the data write-enabled RAID extent, the mapper being used to map a physical space and a virtual logical space, and the degradation number indicating the number of times that the disk slice comprised in the RAID extent changes from being normal to being degraded.

Abstract: Techniques involve detecting whether a transaction of modifying configuration data of a storage system is initiated, the configuration data being stored in a database and a buffered version being stored in memory independent of the database. The techniques further involve in accordance with detection that the transaction is initiated, building a data buffer to buffer a section to be modified, the data buffer being mapped to a storage sector of the memory in which the section is expected to be stored. The techniques further involve determining whether the transaction successfully completed and in accordance with a determination that the transaction fails to successfully complete, releasing the data buffer and aborting the transaction, without modifying the buffered version. Accordingly, the configuration data in the memory remains as the previous version and are not modified before the transaction is successfully completed, which makes it possible to abort the transaction.

Abstract: Embodiments of the present disclosure provide a method, an electronic device, and a computer program product for data compression. The method includes: determining an amount of data to be compressed in a storage system; determining, based on the amount of the data to be compressed, a target compression level for compressing the data to be compressed; and compressing the data to be compressed according to the target compression level. In this way, it is possible to compress data to be compressed using a compression level corresponding to the amount of the data to be compressed, thereby improving the efficiency of data compression in the storage system.

Abstract: In response to failure of a data storage drive, data previously stored on the failed drive is rebuilt on a replacement data storage drive by executing drive rebuild jobs on a first set of processor cores. While the data previously stored on the failed data storage drive is being rebuilt, a second set of processor cores is used to process host I/O (Input/Output) requests. The host I/O requests processed by the second set of processor cores may be a first set of host I/O requests processed during the data rebuild. When a current total number of outstanding host I/O requests exceeds a threshold maximum number of outstanding host I/O requests, at least one processor core in the first set of processor cores may be used to process a second set of host I/O requests while the data previously stored on the failed data storage drive is being rebuilt.

Abstract: In response to detecting the failure of a data storage drive, a drive rebuild operation is performed. The drive rebuild operation is performed by periodically i) calculating a target rebuild rate that enables data previously stored on the failed data storage drive to be completely rebuilt on at least one other data storage drive within an expected drive rebuild time window, ii) calculating a new value for at least one drive rebuild parameter based on a value for the drive rebuild parameter corresponding to the target rebuild rate indicated by a static rebuild rate data structure and a current level of host I/O (Input/Output) activity, and iii) rebuilding the data previously stored on the failed data storage drive on the at least one other data storage drive for a predetermined time period with the at least one drive rebuild parameter set to the new value for the drive rebuild parameter.

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: Techniques for managing a storage system involve flushing a target page in a cache device to a persistent storage device of the storage system. The techniques further involve releasing a resource storing a page descriptor of the target page to a resource pool. The resource pool is configured to provide resources to store page descriptors of pages to be flushed in the cache device. The techniques further involve: if it is determined that an auxiliary descriptor of the target page is located at a tail of a queue of auxiliary descriptors of the pages to be flushed, removing the auxiliary descriptor of the target page from the queue. The auxiliary descriptors of the pages to be flushed are configured to describe the page descriptors of the pages to be flushed. Accordingly, the page flushing performance of the storage system can be improved, thereby improving the input/output performance.

Abstract: Embodiments of the present disclosure provide a method, an electronic device, and a computer program product for data compression. The method includes: determining an amount of data to be compressed in a storage system; determining, based on the amount of the data to be compressed, a target compression level for compressing the data to be compressed; and compressing the data to be compressed according to the target compression level. In this way, it is possible to compress data to be compressed using a compression level corresponding to the amount of the data to be compressed, thereby improving the efficiency of data compression in the storage system.

Abstract: Embodiments of the present disclosure provide a method, an electronic device, and a computer program product for data processing.

Abstract: Technology is disclosed for recovering the consistency of a RAID (Redundant Array of Independent Disks) metadata database when data corruption is detected in the RAID metadata database. The RAID metadata database includes super sectors, stage sectors, and a data region. Valid data within the data region is a contiguous set of sectors extending from a head sector to a tail sector. In response to data corruption in one of the two super sectors, a set of pointers contained in the other super sector is used to identify the head sector and tail sector. In response to data corruption in both super sectors, the head sector and tail sector are located based on the contents of the sectors in the data region. Techniques are also disclosed for recovering consistency when the data corruption occurs in the stage sectors and/or data region.

Abstract: Techniques for managing storage blocks involve: according to a first request for allocating a target number of consecutive storage blocks from a storage device, querying an index table that is used to record index information of a plurality of groups of consecutive idle storage blocks in the storage device to determine a first group of consecutive idle storage blocks from the plurality of groups of consecutive idle storage blocks; allocating the target number of consecutive storage blocks from the first group of consecutive idle storage blocks; updating a bitmap that is used to record states of a plurality of storage blocks in the storage device; and updating first index information of the first group of consecutive idle storage blocks recorded in the index table. Accordingly, such techniques may reduce storage complexity and improve system performance.

Abstract: Managing pool memory in a data storage system includes maintaining free lists for corresponding object sizes. For a memory-consuming request (e.g., host write) an allocation operation is performed and the request data is stored. The allocation operation includes (1) selecting a memory object at least as large as the request size and removing all pages of the selected memory object from the corresponding free list, and (2) selecting pages of the selected memory object to store the request data and marking the selected pages as non-free, and leaving any leftover pages as free pages. For a memory-freeing request (e.g., destaging), a deallocation operation is performed that includes (1) marking the request pages free, and (2) based on neighboring pages being free, merging the request pages and neighboring pages into a corresponding memory object and adding the merged pages to the corresponding free list.

Abstract: A technique manages data within a storage array. The technique involves forming a hybrid tier within the storage array, the hybrid tier including SSD storage and HDD storage. The technique further involves, after the hybrid tier is formed, providing hybrid ubers (or Redundant Array of Independent Disks (RAID) extents) from the SSD storage and the HDD storage of the hybrid tier. The technique further involves, after the hybrid ubers are provided, accessing the hybrid ubers to perform data storage operations.

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 managing disks involve: in response to a number of a plurality of disks to be partitioned being greater than a predetermined number of disks in a disk set, determining a plurality of candidate combinations of disk sets from the plurality of disks. The techniques further involve selecting a target combination from the plurality of candidate combinations, a first disk set of the target combination comprising at least a first subset corresponding to a first disk array, a second disk set of the target combination comprising at least a second subset corresponding to a second disk array, a number of disks in the first subset and a number of disks in the second subset being both equal to a first number and the disks in the first subset being different from the disks in the second subset. Accordingly, such techniques improve the storage efficiency of the disk array.

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.