Abstract: A method and a system for delivering a message in a storage system. In one embodiment of the present invention, there is provided a method for delivering a message in a storage system comprising a first controller, a second controller, a first communication area and a second communication area. The method comprises: in response to receiving a message that is to be delivered from the first controller to the second controller, writing the message to the first communication area that is readable and writable to the first controller and readable to the second controller; and writing an address identifier to the second communication area, the address identifier being used for indicating an address at which the second controller reads the message from the first communication area, the second communication area being readable to the first controller and readable and writable to the second controller.

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: 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: Techniques involve managing a storage space. In response to receiving an allocation request for allocating a storage space, a storage space size and a slice size are obtained. A first storage system and a second storage system are selected from multiple storage systems, the first storage system and the second storage system includes a first storage device group and a second storage device group respectively, and the first storage device group does not overlap the second storage device group. A first slice group and a second slice group is obtained from the first storage system and the second storage system respectively, on the basis of the size of the storage space and the size of the slice. A user storage system is built at least on the basis of the first slice group and the second slice group, so as to respond to the allocation request.

Abstract: A technique involves: in response to receiving a first request for adjusting a first width of a disk array to a second width, obtaining, based on source identification information of a source stripe group in the disk array in the first request, source block identification information of a source block associated with the source stripe group. The technique further involves: determining destination identification information of a destination stripe group associated with the second width for storing data. The technique further involves: storing, based on the source identification information and the destination identification information, source data and metadata for the source data from the source block into a destination block of the destination stripe group, the metadata including node identification information for accessing nodes of the source block. The technique further involves: adjusting the node to access the destination block based on the node identification information.

Abstract: Techniques read data. Such techniques involve: in response to receiving a read request from the user for data on a physical data block, determining whether there is data state information corresponding to the physical data block. The data state information may include a plurality of units for respectively indicating availability of data stored in a plurality of sub-blocks of the physical data block. Such techniques further involve: in response to determining that there is data state information, selecting a target sub-block from the plurality of sub-blocks of the physical storage block based on the data state information. Such techniques further involve: providing the user with data stored in the target sub-block. Such techniques are capable of determining the availability of data at a finer granularity.

Abstract: Techniques support and perform data replication of a virtual machine. Changed data tracking is performed on a storage unit associated with the virtual machine in a storage system, to obtain changed data related information related to the virtual machine, wherein the changed data related information indicates a range and a type of data change related to the virtual machine; from the changed data related information, changed data related information related to the virtual machine within a specified range is obtained in response to receiving an obtainment request of the storage system for changed data related information within the specified range; and the changed data related information within the specified range is sent to the storage system. Accordingly, changed data related information can be provided to a storage system, such that the storage system can implement an optimized data replication operation based on the changed data related information.

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.

Abstract: Techniques manage an input/output (I/O) operation. Such techniques involve estimating a first storage area in a storage device to be accessed by an upcoming random I/O operation, first data being stored in the estimated first storage area. Such techniques further involve, before the random I/O operation is executed, pre-fetching the first data from the first storage area into a cache associated with the storage device. Such techniques enable implementation of the cache pre-fetch for random I/O operations, thereby effectively improving the performance of data access.

Abstract: A storage system and a method for storage control comprises a host device and a switch, and the switch supports remote direct memory access (RDMA). The storage system further comprises a first and second storage control modules, the first storage control module includes a first cache and the second storage control module includes a second cache. The host device, the first and second storage control modules are interconnected via the switch, and the first storage control module is capable of synchronizing the cached data with the second storage control module via the switch. The storage system further comprises a storage array connected to the first and second storage control modules.

Abstract: Described are techniques for data caching. Dirty cached data of a first logical address may be stored in a secondary cache included in multiple caching layers. The multiple caching layers may also include a primary data cache. Two copies of the dirty cached data may be stored in two different cache pages on two different physical devices of the secondary cache. The two cache pages may be marked as dirty indicating that data stored in the cache pages of the secondary cache is a more recent copy of data stored at the first logical address than other data stored on first non-volatile physical storage. Clean cached data of a second logical address may also be stored in the secondary cache where a single copy of the clean cached data is stored in physical storage of the secondary cache.

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: A method and an apparatus for controlling an access to a disk array. The method comprises: receiving a command for writing to a first stripe of the plurality of stripes; and determining a first parity position for the first stripe by searching a mapping table, the mapping table recording a first mapping between the first stripe and the first parity position allocated in the first stripe, the first parity position being arranged in a first disk of the plurality of disks having a minimum wearing level. The embodiments of the present disclosure further disclose a corresponding apparatus. The embodiments of the present disclosure provides a solution for controlling an access to a disk array, which can achieve a dynamic balance of wearing levels among all of the disks in a RAID, thereby making it possible to control or manage a failure order of the disks.

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 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: A method and a system for managing memories in a storage system. In one embodiment of the present invention, there is provided a method for managing memories in a storage system comprising a first controller and a second controller. The method comprising: receiving an allocation request from a second controller in the storage system, where the allocation request requires to allocate available storage spaces from a first memory in the storage system to a second memory in the storage system for use by the second controller; and determining a candidate number of available storage spaces to be allocated from the first memory to the second memory based on first use status of the first memory, wherein the first memory and the second memory are associated with the first controller and the second controller respectively, and the first memory and the second memory are mirrored memories.

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: A method and a system for delivering a message in a storage system. In one embodiment of the present invention, there is provided a method for delivering a message in a storage system comprising a first controller, a second controller, a first communication area and a second communication area. The method comprises: in response to receiving a message that is to be delivered from the first controller to the second controller, writing the message to the first communication area that is readable and writable to the first controller and readable to the second controller; and writing an address identifier to the second communication area, the address identifier being used for indicating an address at which the second controller reads the message from the first communication area, the second communication area being readable to the first controller and readable and writable to the second controller.

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: Techniques for managing metadata at a control device involve: determining, from a cache page corresponding to user data, a first region for storing raw metadata of the user data, the raw metadata including address information for storing the user data in a storage system; in response to the user data being modified, determining updated metadata of the modified user data to update the raw metadata in the first region; and copying the updated metadata to a high-speed memory shared by the control device and another control device. Accordingly, the techniques are capable of reducing the usage frequency of the high-speed memory, thereby extending the service life of the high-speed memory and reducing cost.