Abstract: In certain techniques, a size of a storage space in a first storage device that is allocated for write requests is determined. Write requests are issued by a control device of the storage system to store data into the first storage device and are waiting to be completed. A predetermined release rate of releasing the data stored in the first storage device to a second storage device is determined. An access speed of the first storage device is greater than that of the second storage device. A predetermined completion time of the write requests is determined based on the size of the storage space and the predetermined release rate, and in response to the predetermined completion time exceeding a predetermined time threshold, a throttling indication is transmitted to the control device such that the control device throttles issuing of a further write request for the first storage device.

Abstract: Embodiments of the present disclosure relate to a method and device for cache management. The method includes: receiving an I/O request associated with a processor kernel; in response to first data that the I/O request is targeted for being missed in a cache, determining whether a first target address of the first data is recorded in one of a plurality of cache history lists; in response to the first target address not being recorded in the plurality of cache history lists, storing, in a first node of a first free cache history list, the first target address and an initial access count of the first target address, the first free cache history list being determined in association with the processor kernel in advance; and adding the first node to a first cache history list associated with the I/O request of the plurality of cache history lists.

Abstract: Techniques for storage management involve: detecting a trigger for an adjustment of a redundant level for a set of RAIDs. Each of the set of RAIDs includes one or more RAID extents. Each RAID extent is formed by a plurality of storage extents from a set of storage extents. The set of storage extents is obtained by dividing a plurality of storage disks into storage extents. The plurality of storage extents are located in different storage disks of the plurality of storage disks. The techniques further involve: in response to detecting the trigger, selecting, from the set of RAIDs, a target RAID for which the redundant level is to be adjusted. The techniques further involve: adjusting the redundant level of the target RAID from a first redundant level to a second redundant level. Such techniques can improve the performance of a RAID storage system.

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: A method, computer program product, and computing system for freeing up cache space includes identifying a portion of cache space for removal from a cache system, thus defining a cache portion to be removed, and ceasing to promote the cache portion to be removed. Data that needs to be relocated within the cache portion to be removed is identified, thus identifying flushable data. The flushable data is relocated to a backend storage system associated with the cache portion to be removed.

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, devices and computer readable mediums for data synchronization. A method comprises in response to receiving, at a first processor, a first request to synchronize data, initiating, to a second processor, a first remote direct memory access (RDMA) operation for transmitting the data between a first cache in the first processor and a second cache in the second processor. The method further comprises in response to completion of the first RDMA operation, writing the data into a first persistent storage device coupled to the first processor. The method further comprises transmitting, to the second processor, a command to instruct the second processor to commit the data to a second persistent storage device coupled to the second processor. Moreover, the method further comprises detecting, from the second processor, an acknowledgement for the command, the acknowledgement indicating that the data is synchronized between the first and second processors.

Abstract: A method, computer program product, and computer system for receiving, by a computing device, an I/O request. The I/O request may be processed as a write miss I/O. One or more dirty pages associated with the write miss I/O may be placed into a tree according to a key. It may be determined whether one of a first event and a second event occurs. A data flush may be triggered for the tree when the first event occurs, and the data flush may be triggered for the data flush for the tree when the second event occurs.

Abstract: Embodiments of the present disclosure provide a method of storage management, a storage system and a computer program product. The method comprises determining whether a number of I/O requests for a first page in a disk of a storage system exceeds a first threshold. The method further comprises: in response to determining that the number exceeds the first threshold, caching data in the first page to a first cache of the storage system; and storing metadata associated with the first page in a Non-Volatile Dual-In-Line Memory Module (NVDIMM) of the storage system.

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 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 provide a method, device and computer program product for cache management. The method includes: receiving from a storage device an indication for an invalid storage block in the storage device; in response to receiving the indication, looking up a cache page associated with the invalid storage block in the cache; in response to finding the cache page in the cache, determining validity of data in the cache page; and in response to the data being invalid, reclaiming the cache page.

Abstract: Embodiments of the present disclosure relate to a method and apparatus for managing cache. The method comprises determining a cache flush time period of the cache for a lower-layer storage device associated with the cache. The method further comprises: in response to a length of the cache flush time period being longer than a threshold length of time, in response to receiving a write request, determining whether data associated with the write request has been stored into the cache. The method further comprises: in response to a miss of the data in the cache, storing the write request and the data in the cache without returning a write completion message for the write request.

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 method and device for managing a storage system. In one embodiment of the present invention, there is proposed a method for managing a storage system. In the method, in response to receiving a write request with respect to the data storage system, acquiring a destination address associated with the write request, the destination address being an address in the storage device; a source address associated with data to be written to the destination address is acquired, where the source address is an address in the storage device. The buffer device is searching for the source address on the basis of an association relationship between a page included in the buffer device and an address in the storage device. Information associated with the destination address is updated on the basis of a result of the search.

Abstract: Embodiments of the present disclosure relate to methods, devices and computer readable mediums for managing a storage system. The storage system includes a disk array which includes at least one disk array group. The method comprises in response to receiving a first message indicating that a failure occurs in a disk in the disk array, determining first information on a disk array group that the failed disk belongs to. The method further comprises obtaining a first number of outstanding input/output (I/O) operations on rebuilding the failed disk in the disk array group. The method further comprises determining, based on the first information and the first number, a threshold number of I/O operations that is applicable for the disk array group. In addition, the method further comprises controlling, based on the threshold number, the number of I/O operations initiated to the disk array group.

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), placing the I/O request in a corresponding waiting queue based on a stripe related to the I/O request in the RAID; and in response to the I/O request being granted to process, executing the I/O request based on storage of data of the stripe in a cache memory. Accordingly, by using the cache mechanism for the stripes, the I/O processing efficiency is improved and the user experience is enhanced. Moreover, the count of access to the RAID is reduced, the bandwidth for the backend access is saved and the system performance is improved.

Abstract: Embodiments of the present invention provide a method and a system for managing a storage system. Specifically, in one embodiment of the present invention there is provided a method for managing a storage system, the method comprising: in response to receiving a write request for writing target data to the storage system, writing the target data to an intermediate address range in an intermediate storage area of the storage system; parsing, based on an address mapping of the storage system, a target address range associated with the write request so as to obtain an actual address range; and moving the target data from the intermediate address range to the actual address range. In one embodiment of the present invention there is further provided a corresponding system and apparatus.

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.