Abstract: Embodiments of the present disclosure relate to method, device and computer program product for data backup. The method comprises: in response to receiving from a backup server a data stream to be backed up, dividing the data stream into a plurality of data segments; distributing the plurality of data segments to at least one computing node; in response to receiving an index of a corresponding data segment from a first computing node of the at least one computing node, looking up the index in a global index cache, the index being generated by the first computing node to uniquely identify the data segment, the global index cache storing indexes of data in a backup storage device; in response to the missing index in the global index cache, adding the index into the global index cache; and sending to the first computing node an indication to store the data segment in the backup storage device.

Abstract: A method and device for managing a storage system comprising multiple storage devices in a first layer and at least one backup storage device in a second layer. In response to receiving a request for writing target data to the storage system, storing the target data to a first portion of storage devices among the multiple storage devices in the first layer; storing a first parity, determined on the basis of a first algorithm, of data in the first portion of storage devices to a second portion of storage devices among the multiple storage devices in the first layer; and storing a second parity, determined on the basis of a second algorithm, of data in the first portion of storage devices to a first backup storage device of the at least one backup storage device in the second layer.

Abstract: There is provided a method and apparatus of expanding capacity for a cache array. The method includes in response to detecting that a first new cache disk is to be added to a first cache array, initializing the first new cache disk without disabling other cache disks in the first cache array; allocating a storage space for a cache page metadata based on a result of the initializing; storing the cache page metadata into an initialized directory logical unit number, DIR LUN; storing a copy of the cache page metadata from a memory into the DIR LUN to facilitate the first cache disk to be in a ready state; and in response to the first new cache disk being in the ready state, configuring the first new cache disk as being in an initialized state to expand the capacity of the first cache array.

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: The present invention discloses a method and device for managing a storage system. Specifically, in one embodiment of the present invention there is proposes a method for managing a storage system, the method comprising: dividing a stripe included in a storage array in the storage system into a group of blocks; in response to receiving an allocation request for a storage space in the storage system, determining a space size associated with the allocation request; and building a repository based on one or more blocks selected from the group which match the space size, the repository being defined using an address mapping including addresses of the one or more blocks in the storage system. In one embodiment of the present invention there is proposed a device for managing a storage system.

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: Embodiments of the present disclosure relate to a method and a device for cache management. The method includes: in response to receiving a write request for a cache logic unit, determining whether a first cache space of a plurality of cache spaces associated with the cache logic unit is locked; in response to the first cache space being locked, obtaining a second cache space from the plurality of cache spaces, the second cache space being different from the first cache space and being in an unlocked state; and performing, in the second cache space, the write request for the cache logic unit.

Abstract: A method for the adsorption separation of propylene and propyne, comprising selectively adsorbing propyne from a mixed gas of propylene and propyne using an anion-containing metal-organic framework material as an adsorbing agent so as to obtain a purified propylene gas. The anion-containing metal-organic framework material is used as an adsorbing agent in the method, and the adsorbing agent is a kind of highly ordered microporous organic-inorganic hybrid material, with the pore size thereof being adjustable within the range of 0.4-1.2 nm, and the pore volume thereof being adjustable within the range of 0.1-1.2 cm3/g. A large number of anionic active sites and a highly ordered spatial arrangement thereof allow the adsorbing agent to exhibit excellent propyne adsorption properties. Thus, the adsorbing agent has a very high propyne selectivity and adsorption volume.

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: 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: Embodiments of the present disclosure relate to communications between virtual dual control modules in a virtual machine environment. A computer-implemented method and an electronic device are disclosed. The method includes deploying a first virtual control module and a second virtual control module in a virtual storage, the first virtual control module and the second virtual control module are redundant with each other. The method further comprises creating a virtual Peripheral Component Interconnect Express (PCIe) switch for emulating a physical PCIe switch, and synchronizing cache data between the first virtual control module and the second virtual control module via the virtual PCIe switch.

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: Techniques are disclosed which monitor the distribution of I/O activity across the storage drives of a data storage system and detect non-uniform distributions of I/O operations across the storage drives by monitoring I/O operations directed to disk extents supporting mapped RAID extents. In response to detecting non-uniform distributions of I/O operations across the storage drives, these techniques identify LUNs with non-uniform I/O patterns and redistribute data stored in those LUNs across RAID extents supporting those LUNs.

Abstract: Embodiments of the present disclosure provide a method for establishing a multi-tier flash cache using spare drives. In some embodiments, there is provided a computer-implemented method, comprising: in response to receiving an I/O request, determining whether there is a free page in a main cache; in response to determining that there is no free page in the main cache, establishing a secondary cache by selecting at least one spare drive from spare drives; flushing data from a cold page in the main cache to the secondary cache, an access frequency of the cold page being lower than a predetermined threshold; and writing data related to the I/O request from a persistent storage device to the cold page.

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: Embodiments of the present disclosure provide a method for managing a storage system, an apparatus and a computer readable storage medium. The method comprises: determining a permitted concurrency number for respective access to multiple storage devices in the storage system by a multi-level cache device of the storage system, the permitted concurrency number being associated with a state of the multiple storage devices; in response to receiving an access request for the storage system, determining a cache device in the multi-level cache device corresponding to the access request; determining whether a current concurrency number of access to the multiple storage devices in the cache device reaches the permitted concurrency number; and in response to determining that the current concurrency number fails to reach the permitted concurrency number, executing the access request for the storage system.

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: Embodiments of the present disclosure provide a cache system and associated method. The cache system includes a first pipeline module including a first plurality of sequential processing phases for executing a plurality of operations. The first plurality of operations is executed in response to Input/Output (I/O) requests of a first plurality of types for the persistent storage device, and each of the first plurality of operations is a common operation for the I/O requests of at least two of the first plurality of types. The cache system also includes a control module configured to: determine a first type of a first pending processing I/O request for the persistent storage device, and in response to the first type being one of the first plurality of types, cause the first pipeline module to be executed to process the first pending processing I/O request.

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: Techniques of protecting data involve storing a data structure in a data storage system that associates indices with respective keys. In this data structure, each index corresponds to a point in time when a respective key was put into effect. Each key may then be used to decrypt data stored in the data storage system that was encrypted during a time interval following the point in time when the respective key was put into effect, but before a later key was put into effect. During a key update process, a new key is put into effect and a new entry is created in the data structure that associates a new index with the new key.