Abstract: Techniques for managing data blocks involve: generating, based on a first hash algorithm, a first fingerprint for a first block. The techniques further involve: if it is determined that there is a second fingerprint, in a fingerprint database, that is generated for a second block based on the first hash algorithm and matches the first fingerprint, determining whether there is a third fingerprint, in the fingerprint database, that is generated for the second block based on a second hash algorithm. The techniques further involve: if it is determined that the third fingerprint exists in the fingerprint database, generating a fourth fingerprint for the first block based on the second hash algorithm; and determining whether the first block and the second block are duplicate by comparing the third fingerprint and the fourth fingerprint. Such techniques can effectively reduce the overhead of identifying duplicate data blocks in data deduplication.

Abstract: Techniques perform I/O management. The techniques involve: in response to receiving an I/O request for a redundant array of independent disks (RAID), determining a stripe of the RAID related to the I/O request; determining metadata corresponding to the stripe, the metadata indicating validity of current data in a corresponding data block of the RAID, the data block comprising one or more stripes; in response to the metadata indicating that the current data is valid, executing the I/O request by accessing the RAID; and in response to the metadata indicating that the current data is invalid, responding to the I/O request with zero data as the current data. Accordingly, disk access is reduced, metadata cache efficiency is increased, I/O performance is improved and the RAID reliability is enhanced.

Abstract: A storage management technique involves: receiving from a requesting node a write request for writing target data into a first target storage space in a redundant array of independent disks (RAID); if a storage device associated with the first target storage space does not fail, acquiring first data stored in the first target storage space and a first parity value corresponding to the requesting node and stored in a parity storage space; determining a target parity value based on the target data, the first data, and the first parity value; and updating a stripe with the target data and the target parity value. Accordingly, locks caused by updating the parity value can be avoided, so that different nodes can perform parallel write to different storage spaces in the same stripe in the RAID.

Abstract: A method is used in improving rebuilding in data storage. The generation number of a PLB is compared with a generation number of a partition corresponding to the PLB. The data of the PLB is rebuilt based on the comparison.

Abstract: A storage management technique involves: receiving from a requesting node a write request for writing target data into a first target storage space in a redundant array of independent disks (RAID); if a storage device associated with the first target storage space does not fail, acquiring first data stored in the first target storage space and a first parity value corresponding to the requesting node and stored in a parity storage space; determining a target parity value based on the target data, the first data, and the first parity value; and updating a stripe with the target data and the target parity value. Accordingly, locks caused by updating the parity value can be avoided, so that different nodes can perform parallel write to different storage spaces in the same stripe in the RAID.

Abstract: Embodiments of the present disclosure provide a solution of evaluating a rebuilding performance of a redundant array of independent disks. In some embodiments, there is provided a computer-implemented method, comprising: simulating, based on a first group of redundant arrays of independent disks, a rebuilding process for a second group of redundant arrays of independent disks; obtaining a first performance metric of the simulated rebuilding process; and identifying a factor associated with the rebuilding performance of the second group of redundant arrays of independent disks based on the first performance metric.

Abstract: Techniques for information update involve: updating, at a first node, first information in a first memory and second information associated with the first information, wherein the first information needs to be persistently stored, and the second information can be obtained from the first information and does not need to be stored persistently; storing the updated first information and the updated second information into a first region and a second region of a first persistent storage device, respectively; synchronizing the updated first information and the updated second information to a second node; and validating the updated first information stored in the first region and invalidating the updated second information stored in the second region based on a determination that the synchronization is successful. Such techniques can achieve incremental update of non-persistent information, thereby improving system performance.

Abstract: A method of correcting errors in a data storage system including a first node, a second node, and shared persistent storage (the first and second nodes being configured to process data storage requests) is provided. The method includes (a) reading cached pages from a first cache disposed within the first node, the cached pages being cached versions of respective persistent pages stored in the shared persistent storage; (b) in response to determining that one of the cached pages is corrupted, requesting that the second node return to the first node a corresponding remote page from a second cache disposed within the second node, the cached page and the remote page each caching a same persistent page of the shared persistent storage; and (c) in response to determining that the remote page received from the second node by the first node is not corrupted, correcting the cached page using the remote page.

Abstract: Techniques for rebuilding a failed drive of a plurality of drives are provided. The techniques include: (a) determining a number of empty data stripes that have been allocated from the plurality of drives; (b) applying a set of decision criteria to the determined number to yield a decision, wherein applying the set of decision criteria yields a first decision at a first time and a differing second decision at a second time; (c) in response to the first decision at the first time, deallocating an empty data stripe that was allocated from the plurality of drives to yield a plurality of data extents on disparate drives of the plurality of drives and continuing to rebuild the failed drive onto at least one of the plurality of data extents; and (d) in response to the second decision at the second time, pausing rebuilding the failed drive until applying the set of decision criteria yields the first decision.

Abstract: Dirty pages of cached user data are persistently stored to page buffers that are allocated from a page buffer pool in a persistent data storage resource of a data storage system, and are indicated by page descriptors that are stored at a head of a temporally ordered page descriptor ring as the dirty pages are stored to the page buffers. The disclosed technology performs a flush operation by selecting a work-set of non-sequential page descriptors within the page descriptor ring, flushing dirty pages from page buffers indicated by the page descriptors in the work-set to non-volatile data storage drives of the data storage system, and storing, for each one of the page buffers indicated by the page descriptors in the work-set, an indication that the page buffer is available for re-use.

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: A method is used in improving rebuilding in data storage. The generation number of a PLB is compared with a generation number of a partition corresponding to the PLB. The data of the PLB is rebuilt based on the comparison.

Abstract: A technique of protecting data in a data storage system includes, in response to receiving a write request that specifies data to be written in the data storage system, calculating an error detection code (EDC) of the specified data. The technique further includes persisting the specified data and the EDC in persistent cache and, in response to receiving a read request for reading the specified data, validating the specified data using the EDC before returning the specified data in satisfaction of the read request.

Abstract: Technology for configuration metadata recovery that detects a reliability failure regarding configuration metadata stored in non-volatile data storage of a data storage system. The configuration metadata indicates how a metadata database is stored in the non-volatile data storage of the data storage system. In response to detection of the reliability failure regarding the configuration metadata, the technology identifies valid generations of the configuration metadata that are currently stored in the non-volatile data storage of the data storage system, and determines a user-selected one of the valid generations of the configuration metadata. The metadata database is accessed based on the user-selected one of the valid generations of the configuration metadata.

Abstract: Techniques provide storage management. Such techniques involve storing cache data of a buffer memory corresponding to a storage disk group into a standby disk based on a determination that the number of disks in a first disk set in the storage disk group is less than a threshold number of disks. The techniques further involve adjusting at least one disk in a second disk set to the first disk set so that the number of disks in the adjusted first disk set and the number of disks in the adjusted second disk set are both greater than or equal to the threshold number of disks. The techniques further involve loading a first part of data in the standby disk into the adjusted first disk set. In addition, the techniques further involve loading a second part of data in the standby disk into the adjusted second disk set.

Abstract: An integrated circuit product includes a first layer of insulating material including a first insulating material. The first layer of insulating material is positioned above a device layer of a semiconductor substrate. The first layer of insulating material has a lowermost surface positioned above an uppermost surface of a gate of a transistor in a device layer of a semiconductor substrate. The device layer includes transistors. A metallization blocking structure is positioned in an opening in the first layer of insulating material. The metallization blocking structure has a lowermost surface above the uppermost surface of the gate and includes a second insulating material that is different from the first insulating material. The metallization blocking structure includes a second insulating material that is different from the first insulating material. A metallization trench is defined in the first layer of insulating material on opposite sides of the metallization blocking structure.

Abstract: Techniques perform data storage. Such techniques may involve writing metadata to a first cache of a first processor, the metadata indicating allocation of a storage resource to user data. Such techniques may further involve determining an address range of the metadata in the first cache. Such techniques may further involve copying only data stored in the address range in the first cache to a second cache of a second processor. Accordingly, the data transmission volume between two processors is reduced, which helps to improve the overall performance of a storage system.

Abstract: a method and an apparatus for maintaining reliability of a mapped redundant array of independent disks. The method comprises: determining a first data loss probability, the first data loss probability indicating reliability of a traditional redundant array of independent disks; determining a second data loss probability, the second data loss probability indicating reliability of the mapped redundant array of independent disks; and determining, based on the first and second data loss probabilities, a condition for maintaining the reliability of the mapped redundant array of independent disks. Compared with the prior art, embodiments of the present disclosure can effectively predict the reliability of a mapped RAID through comparison with a traditional RAID, so as to be capable of determining a reliability relationship between the traditional RAID and the mapped RAID. In this way, the reliability of the traditional RAID will not be degraded when being expanded into the mapped RAID.

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: 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.