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 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 involve: in response to a number of errors of an error type in a storage disk increasing, determining an adjustment rate for a health value of the storage disk based on a total usage time length of the storage disk, where a longer total usage time length corresponds to a higher adjustment rate, and the health value indicates a health condition of the storage disk with respect to the error type. The techniques further involve increasing the adjustment rate based on a total input/output (I/O) number of the storage disk, where a greater total number of I/Os corresponds to a greater increment. The techniques further involve adjusting the health value with the adjustment rate. Such techniques can improve the accuracy of evaluating the health condition of the storage disk.

Abstract: Embodiments of the present disclosure provide a method, an apparatus and a computer program product for managing an input/output (I/O). The method comprises, in response to receiving a first I/O request of a first type for a storage device, determining whether there exists at least one credit available to the first type of I/O requests. Each of the at least one credit indicates I/O processing capability reserved by the storage device for the first type of I/O requests. The method further comprises allocating a first credit to the first I/O request based on a result of the determining. The method further comprises performing, by using the first credit, an I/O operation requested by the first I/O request on the storage device. Moreover, the method further comprises, in response to completion of the I/O operation, recycling the first credit for use by a subsequent I/O request. Embodiments of the present disclosure can implement dynamic allocation of I/O processing capability for different types of I/Os.

Abstract: Embodiments of the present disclosure relate to methods and apparatuses for data copy. A method comprises receiving, from a client module in a first processing unit, a read request for reading data from a first storage region. The method further comprises, in response to determining from the read request that the data is to be copied, obtaining, from a cache, a first bitmap associated with the first storage region, the first bitmap indicating if the first storage region is filled with zero. The method further comprises, in response to determining from the first bitmap that the first storage region is filled with zero, sending, to the client module, an indication that the data is zero.

Abstract: Techniques for storage management involve determining, in response to a detection that a disk changes from an unavailable state to an available state, at least one candidate storage unit associated with the disk; acquiring historical access information about the at least one candidate storage unit, the historical information comprising information related to a write request directed to the at least one candidate storage unit when the disk is in the unavailable state; determining a target storage unit from the at least one candidate storage unit based on the historical access information; and rebuilding the target storage unit. Such techniques may, in a low-cost manner, improve rebuilding efficiency and reliability of a storage system.

Abstract: Embodiments include a method performed by a computing device. The method includes (a) receiving a plurality of access requests to access data of a multilayered storage system; (b) in response to determining that a first access request can be served from a top data layer, executing the first access request by accessing the top data layer; (c) in response to determining that a second access request cannot be served from the top data layer, determining whether a current concurrency number of the top data layer is less than a permitted concurrency number (PCN) of the top data layer; and (d) in response to determining that the current concurrency number of the top data layer is not less than the PCN, waiting until the current concurrency number of the top data layer is less than the PCN and then executing the second access request by accessing another data layer below the top layer.

Abstract: Techniques expand storage space. Such techniques can create a storage stripe group during a shuffling operation after a storage device being added, without waiting for full completion of the shuffling operation. Such techniques can effectively reduce the waiting time for creating the storage stripe group. Besides, such techniques can support partial mapping of the storage stripe group, such that the storage resources mapped to the storage stripe group can be rapidly utilized.

Abstract: Embodiments of the present disclosure provide a method and device for RAID rebuilding. In some embodiments, there is provided a computer-implemented method. The method comprises: determining a spare redundant array of independent disks (RAID) group with spare capacity from a plurality of disks included in at least one RAID group of a storage pool; building spare logic units from the spare RAID group; and in response to a RAID group of the at least one RAID group of the storage pool being in a degradation state, rebuilding a failed disk in a degraded RAID group using the spare logic units.

Abstract: Embodiments of the present disclosure provide a cache management method, storage system and computer program product. The cache management method includes determining an access frequency for each of a plurality of cache pages in a storage system. The method further includes organizing the plurality of cache pages into a plurality of queues based on the access frequency. The method further includes allocating solid-state disks for the plurality of queues based on the access frequency, so that queues where pages with higher access frequency are located have more solid state disks.

Abstract: The present application discloses a coal consumption online measuring system, which belongs to the field of analysis and measurement technology. The system includes an equivalent atomic number measuring device, a flow rate measuring device, an ash content measuring device, a volatile content measuring device, a moisture content measuring device and a data acquisition and processing device. The data acquisition and processing device iteratively corrects the measured real-time density, real-time ash content, real-time moisture content and/or real-time volatile content; and the data acquisition and processing device performs online calculation of the coal consumption according to a real-time volume flow rate and the iteratively-corrected real-time density, real-time ash content, real-time moisture content and real-time volatile content.

Abstract: Techniques manage addresses in a storage system. In such techniques, an address page of an address pointing to target data in the storage system is determined in response to receiving an access request for accessing data in the storage system. A transaction for managing the address page is generated on the basis of the address page, here the transaction at least comprises an indicator of the address page and a state of the transaction. A counter describing how many times the address page is referenced is set. The transaction is executed at a control node of the storage system on the basis of the counter. With such techniques, the access speed for addresses in the storage system can be accelerated, and then the overall response speed of the storage system can be increased.

Abstract: Techniques for managing a storage system involve: determining a size of a data information indicating area in the storage system, the data information indicating area indicating content information related to a slice group including multiple slices, the slice group being the smallest data granularity for storage processor access associated with the storage system; determining a correspondence between the size of the data information indicating area and a size of the slice group; and determining, based on the size of the data information indicating area and the correspondence, the size of the slice group. Accordingly, bandwidth of a communication message interface which interconnects storage processors and is utilized heavily by system components can be saved. Additionally, cross-storage processor message communication for access to data information indicating area from input and output paths can be eliminated.

Abstract: Techniques for storage management involve determining an independent redundant disk array RAID associated with a first set of storage disks, a first portion of storage blocks corresponding to the RAID being located in the first set of storage disks; determining, from the first set of storage disks, a plurality of storage disks corresponding to the RAID; and updating a set of association degrees of the first set of storage disks to indicate data coupling between storage disk pairs in the plurality of storage disks. Accordingly, the data coupling degree between storage disks can be determined more accurately.

Abstract: A method, computer program product, and computer system for executing one of a reboot and a startup process. A write I/O may be received at a DRAM cache. Data may be written to at least two different NVMe devices. When the data of the write I/O is completely written to the at least two different NVMe devices, a response may be sent to a driver layer.

Abstract: Embodiments of the present disclosure relate to a method, device and computer readable medium for managing storage. The method comprises: in response to obtaining, at a first storage processor, an access request for a storage unit, determining whether the storage unit is currently accessible, the storage unit including at least one storage area. The method further comprises: in response to the storage unit being currently inaccessible, determining whether the first storage processor has an access right to the storage unit. In addition, the method further comprises: in response to the first storage processor having no access right, requesting a second storage processor for the access right, the second storage processor being associated with a mirror storage unit of the storage unit, and the first and second storage processors having exclusive write access rights.

Abstract: A storage system is associated with at least one part of multiple storage devices in a resource pool, a part of a storage space in a storage device being inaccessible to the storage system. Techniques involve: identifying an extent within the part of the storage space in the storage device as a free extent; selecting a group of storage devices each with a free extent from the multiple storage devices in response to determining a virtual address range in the storage system as specified by an access request is inaccessible; mapping the virtual address range to a physical address range of the free extents in the group of storage devices; and allocating a storage space specified by the physical address range to the storage system. Therefore, the expansion of the resource pool can be implemented more conveniently and rapidly, and performance of the storage system can be improved.

Abstract: A method and apparatus for managing data access comprises: receiving a write request for writing data into one or more storage blocks; in response to determining that a storage block is unavailable, writing a part of the data into a virtual storage block corresponding to the storage block, the part of the data being required to be written into the storage block; and in response to determining that the storage block becomes available, copying the part of the data from the virtual storage block to the storage block. The embodiments of the present disclosure further disclose a corresponding apparatus. By introducing the virtual storage blocks in the data access, the embodiments of the present disclosure can realize the parallel data transfers of a plurality of writes and thus greatly improve the data writing performance of the system.

Abstract: In techniques for selecting a rebuild destination in a storage system, a failed stripe group associated with a failed extent group in a failed storage device among storage devices is detected. A group of normal storage devices other than the failed storage device is determined. Regarding a normal storage device in the group of normal storage devices, a first count for the normal storage device is obtained, the first count representing a number of failed stripes which are allowed to be rebuilt to the normal storage device in the failed stripe group. Based on the first count, a destination storage device is selected from the group of normal storage devices for rebuilding a failed stripe in the failed stripe group. During rebuild, a destination for rebuilding the failed stripe may be effectively selected, and extents in reserved space in the storage system may be more fully utilized.

Abstract: Techniques provide cache service in a storage system. Such techniques involve a storage cell pool, a cache and an underlying storage system. The storage cell pool includes multiple storage cells, a storage cell among the multiple storage cells being mapped to a physical address in the underlying storage system via an address mapping of the storage system. Specifically, an access request for target data at a virtual address in the storage cell pool is received, and the type of the access request is determined. The access request is served with the cache on the basis of the determined type, where the cache is used to cache data according to a format of a storage cell in the storage cell pool. The cache directly stores data in various storage cells in the pool that is visible to users, so that response speed for the access request may be increased.