Abstract: Embodiments of the present disclosure provide a method, a device, and a computer program product for storage management. The method for storage management includes: acquiring a reading request for a first target file, the reading request including a first target file name of the first target file. The method further includes: determining a first target characteristic value for the first target file based on the first target file name. The method further includes: determining first target index information for the first target file from a mapping from characteristic values to index information based on the first target characteristic value, wherein the first target index information is used to index the first target file from a merged file. The method further includes: reading the first target file included in the merged file from a storage system based on the first target index information.

Abstract: A data compression technique involves: selecting, from a data block, a plurality of bit strings as sample data. The technique further involves: determining a set of characters included in the sample data. Each character in the set of characters is represented by at least one bit string among the plurality of bit strings. The technique further involves: compressing the data block if statistical characteristics of the set of characters match predetermined statistical characteristics. Accordingly, incompressible data can be filtered out efficiently and accurately, so as to utilize computing resources more efficiently.

Abstract: Storage management techniques involve determining, if it is determined that lock information associated with a lock operation performed on an object is to be inserted into a storage device, a target digest for representing the lock information; determining whether an idle index not associated with a historical digest exists in an index array for indicating a plurality of storage positions in the storage device; and inserting, if it is determined that an idle index exists in the index array, the lock information into a target storage position in the plurality of storage positions by associating the target digest with the idle index. Accordingly, lock information can be quickly inserted and cleared, thereby improving the system performance.

Abstract: A storage system includes stripes, extents included in one stripe among the stripes reside on storage devices in the storage system, respectively, and the storage system includes an address mapping between the stripe and storage devices where the extents reside. Regarding one extent, a storage device where the extent resides is determined among the storage devices based on the address mapping. The stripe is added to a rebuild list of the storage system in accordance with determining the storage device is a failed storage device, the rebuild list comprising a stripe that is to be rebuilt in the storage system. The storage system is rebuilt based on stripes in the rebuild list. Accordingly, the performance of a rebuild operation may be improved, and the time for the rebuild operation may be reduced. Further, there is provided a corresponding device and computer program product for managing a storage system.

Abstract: Technique determine (or detect) duplicated data. The techniques involve: in response to determining that data at a first position in input data is the same as predetermined data, determining a feature value of a selected portion of input data; determining whether the feature value matches with a pre-stored duplicated data pattern in a duplicated data pattern list; and in response to determining that the feature value matches with the duplicated data pattern, determining an association of the input data with reference data which is associated with the matched pattern.

Abstract: Techniques perform cache management. Such techniques involve: obtaining a first cache page of the cache to be flushed, the first cache page being associated with a target storage block in a storage device; determining from the cache a set of target cache pages to be flushed, each of the set of target cache pages being associated with the target storage block; and writing data in the first cache page and data in each of the set of target cache pages into the target storage block simultaneously.

Abstract: Techniques for storing data involve estimating a hit ratio of a digest cache associated with a target storage device, the digest cache recording a digest of data that is stored in the target storage device after preprocessing; generating, according to a determination that the hit ratio is lower than a predetermined threshold, a digest for target data to be stored and performing the preprocessing; and storing, according to a determination that the digest of the target data is missing in the digest cache, the preprocessed target data in the target storage device, and recording the digest of the target data in the digest cache. Such techniques can achieve good system performance in both cases of high data repetition and low data repetition.

Abstract: Techniques for tracking a lock involve creating an event comprising object information, and extracting the object information in the event through a thread in a thread pool. Such techniques further involve recording lock information comprising the object information according to a determination that the thread executes a lock operation. Such a lock tracking technique for a threading model can record lock information of an object when a thread performs locking and unlocking, and realize tracking of a lock operation and generating a lock analysis report.

Abstract: Techniques involve: selecting a stream from a plurality of streams having respective update frequencies, the update frequency of the selected stream matching an update frequency of to-be-written data; determining a label of the data based on a label of the selected stream; and sending a write request for the data to a storage system, the write request comprising the label of the data, so that the storage system performs a write operation for the data based on the stream identified by the label. Accordingly, a write amplification factor can be reduced, thereby increasing the effective life of a storage device and improving read and write performance of the storage system.

Abstract: Techniques involve receiving a write request for writing metadata of a file system into a solid state disk having a multi-level cell, and then caching the to-be-written metadata into a memory. The techniques further involve sequentially writing the cached metadata into the solid state disk by redirect-on-write. Accordingly, there is a file system implemented for properties of a solid state disk having a multi-level cell. Such techniques are able to provide completely sequential write of metadata of the file system by supporting redirect-on-write, thereby reducing the write amplification of the solid state disk and improving the performance of the file system.

Abstract: Techniques for cache management involve accessing, when a first data block to be accessed is missing in a first cache, the first data block from a storage device storing the first data block; selecting, when the first cache is full and based on a plurality of parameters associated with a plurality of eviction policies, an eviction policy for evicting a data block in the first cache from the plurality of eviction policies, the plurality of parameters indicating corresponding possibilities that the plurality of eviction policies are selected; evicting a second data block in the first cache to a second cache based on the selected eviction policy, the second cache being configured to record the data block evicted from the first cache; and caching the accessed first data block in the first cache. Such techniques can improve the cache hit rate, thereby improving the access performance of a system.

Abstract: In accordance with certain techniques, prefetching operation may be divided into two parts: a trigger part and an execution part, thereby simplifying the prefetching process. Such techniques may further support prefetching of concurrent flows and enhance anti-interference capability. Certain techniques involve receiving a read request for a memory page, and determining whether the read request satisfies a trigger condition of a prefetching operation for the memory page. These certain techniques further involve, in response to the read request satisfying the trigger condition, determining a window size of the prefetching operation based on historical information of historical prefetching operations for the memory page, and triggering, based on the window size, execution of the prefetching operation.

Abstract: Techniques delete snapshots. The techniques involve: in response to a data block to which a plurality of snapshots of a file to be deleted point being shared, determining whether a physical address of the data block to which the plurality of snapshots to be deleted point is the same as a target physical address of a data block to which a target snapshot of the file points. The techniques further involve: in response to the physical address of the data block to which the plurality of snapshots to be deleted point being the same as the target physical address, setting flag bits associated with the plurality of snapshots to be deleted to a first state. The techniques further involve: in response to detecting the first state, updating a target weight with a sum of weights of the plurality of snapshots to be deleted (e.g., respective quotas).

Abstract: Techniques to process metadata involve: in response to receiving a modification transaction for metadata on a computing device, acquiring information related to a busyness degree of the computing device; and according to at least a determination that the busyness degree is greater than a threshold degree, modifying the metadata in a metadata storage apparatus of the computing device directly without generating a log related to the modification transaction in a log storage apparatus of the computing device. Accordingly, such techniques can achieve good processing performance irrespective of a busy state or non-busy state of a computing device. In particular, when the computing device is in a busy state, a newly triggered modification transaction can still be timely executed, thereby improving IOPS performance of the computing device in a busy state.

Abstract: A method is used in detecting slow storage device operations in a storage system. Information regarding a set of storage device operations performed on a storage device in the storage system is monitored in real time. The information is analyzed in real time. A determination is made from the analysis whether the storage device can be identified as a slow storage device. At least one action is performed on the storage system, while the storage system continues to operate, to isolate the slow storage device.

Abstract: Techniques for storage management involve: in accordance with a determination that an input/output (I/O) request of a storage system is received, determining a target storage device to which the I/O request is directed. The techniques further involve: in accordance with a determination that the target storage device is a storage device of a first type, processing the I/O request by accessing a memory of the storage system. The techniques further involve: in accordance with a determination that the target storage device is a storage device of a second type different from the first type, processing the I/O request without accessing the memory, the storage device of the second type having an access speed higher than that of the storage device of the first type. Accordingly, such techniques can improve performance of a storage system.

Abstract: A storage system includes stripes, extents included in one stripe among the stripes reside on storage devices in the storage system, respectively, and the storage system includes an address mapping between the stripe and storage devices where the extents reside. Regarding one extent, a storage device where the extent resides is determined among the storage devices based on the address mapping. The stripe is added to a rebuild list of the storage system in accordance with determining the storage device is a failed storage device, the rebuild list comprising a stripe that is to be rebuilt in the storage system. The storage system is rebuilt based on stripes in the rebuild list. Accordingly, the performance of a rebuild operation may be improved, and the time for the rebuild operation may be reduced. Further, there is provided a corresponding device and computer program product for managing a storage system.

Abstract: Embodiments of the present disclosure relate to method and device for data read/write. The method comprises: in response to receiving a first read/write request for a first target area, determining whether there is a second read/write request under execution in conflict with the first read/write request, a second target area for the second read/write request at least partially overlapping with the first target area, and at least one of the first read/write request and the second read/write request being a write request; and in response to determining there being the second read/write request in conflict, suspending the first read/write request while maintaining a sub-area of the first target area in an unlocked state, the sub-area not overlapping with the second target area.

Abstract: Techniques process data. The techniques involve determining priority of a plurality of cores of a processor based on metadata stored in a plurality of queues associated with the plurality cores, respectively, the metadata being related to data blocks to be processed that are associated with the respective cores, and the metadata in each of the queues being sorted by arrival times of the respective data blocks to be processed. The techniques further involve storing core identifiers of the plurality of cores into a cache by an order of the priorities. By means of at least some of the above techniques, quick insertion of metadata can be realized through multiple queues and the efficiency of determining data blocks to be processed is improved based on sorting of the cores.

Abstract: A method and device for executing test cases includes obtaining a set of test cases to be executed, and determining a test platform type and a test script associated with each test case in the set of test cases based on a knowledge base. The set of test cases may be divided into a plurality of test subsets or test suites based on the test platform type, and test cases in each test subset executed using the respective test environment and test script. The test suites may be generated automatically based on the knowledge base, and the respective test environment and test script are used for executing each test suite. Automatic generation and execution of the test suites can improve the operation efficiency for test cases.