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 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 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 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: A method and a system for locking a storage area in a storage system. There is provided a method for locking a storage system in a storage system, where the storage system comprises a first controller, a second controller, a first communication area and a second communication area. The method comprises: a first lock flag associated with the storage area is written to the first communication area in response to receiving at the first controller a data access request with respect to the storage area, where the first communication area being readable and writable to the first controller and being readable to the second controller. A second lock flag associated with the storage area is read from the second communication area, where the second communication area being readable to the first controller and being readable and writable to the second controller. The storage area is locked by the first controller in response to the second lock flag indicating that the storage area is not locked by the second controller.

Abstract: Described herein are techniques for use in balancing allocated cache pages among storage devices in a flash cache. The techniques comprise determining an expected number of allocated cache pages in connection with a non-volatile storage device that forms at least part of a flash cache. The techniques also comprise performing a comparison between the expected number of allocated cache pages and an actual number of allocated or free cache pages in connection with the non-volatile storage device. The techniques further comprise selecting, based on the comparison, a free cache page in connection with the non-volatile storage device to allocate as a cache page.

Abstract: Embodiments of the present invention relate to a method and system for managing data access in a storage system. A method for managing data access in a storage system, the method comprising: obtaining state information about available resources in a storage control node in the storage system; determining, based on the state information, a credit score descriptive of processing capacity of the storage control node for data access; and publishing the credit score so as to notify a host of the processing capacity of the storage control node for the data access.

Abstract: Embodiments of the present disclosure relate to a method and device for flushing pages from a solid-state storage device. Specifically, the present disclosure discloses a method, of flushing pages from a solid-state storage device comprising: determining a first number based on a period length of one flushing cycle and a period length required for building one flushing transaction, the first number indicating a maximum number of flushing transactions that can be built in the flushing cycle; and flushing pages from the solid-state storage device with an upper limit of the first number in the flushing cycle. The present disclosure also discloses a device for flushing pages from a solid-state storage device and a computer program product for implementing steps of a method of flushing pages from a solid-state storage device.

Abstract: Systems, methods, and computer readable media are disclosed. A map including the number of dirty cache pages stored in the flash disk cache for each VLUN of the plurality of VLUNs on the storage system is maintained, by the storage system. A flash disk cache error requiring the storage system to take the flash disk cache offline is detected. In response to detecting the flash disk cache error a first one or more VLUNs of the plurality of VLUNs with at least one dirty cache page stored in the flash disk cache are identified by the storage system based on the map. The first one or more VLUNs are taken offline by the storage system. The flash disk cache is taken offline by the storage system. A second one or more VLUNs comprising VLUNs of the plurality of VLUNs without dirty cache pages stored in the flash disk cache are maintained online by the storage system.

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: 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 invention provide a method and a system for managing a storage system. In one embodiment of the present invention, there is provided a method for managing a storage system, where the storage system comprises a first controller, a second controller, a first communication area as well as a second communication area.

Abstract: Various embodiments of the present disclosure generally relate to a fault processing method, system and computer program product. Specifically, the method may comprise determining a plurality of devices to be detected and corresponding device attributes. The method may also comprise performing a first fault detection for the plurality of devices based on the device attributes, the first fault detection being based on a first fault diagnosis rule that is generic for the plurality of devices. Besides, the method may also comprise: in response to a first device in the plurality of devices being determined to have a fault in the first fault detection, performing a first fault processing to the first device, the first fault processing being based on a first fault processing rule that is generic for the plurality of devices.

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: Securing encryption keys in a data storage system using three layer key wrapping that encrypts a data encryption key using a key encryption key, encrypts the key encryption key using a controller encryption key, and encrypts the controller encryption key using a public key of an asymmetric key pair. The private key is stored on a removable storage device. A separate encryption accelerator component decrypts the encryption keys in order to encrypt and/or decrypt host data from a memory of a storage processor. The removable storage drive must be inserted into a receptacle of the encryption accelerator for encryption and/or decryption to be performed, since the encryption accelerator accesses the private key from the removable storage device in order to decrypt the encrypted controller key. The encryption accelerator generates key handles for the storage processor to use when requesting encryption and/or decryption operations.

Abstract: Embodiments of the present disclosure relate to a method and an apparatus for operating a hybrid storage device, the hybrid storage device including a storage device of a first type and a storage device of a second type that is different from the first type, the method comprising: synchronously writing data in the storage device of the first type and the storage device of the second type. By using the embodiments of the present disclosure, the actual storage space may be increased, and the service life of the storage device may be prolonged.

Abstract: Embodiments of the present disclosure relate to a method and apparatus for facilitating wear leveling of a solid state disk (SSD). The method comprises obtaining a performance parameter of a SSD device of a plurality of SSD devices in the SSD cache, and the SSD device includes one or more SSD disks. The method further comprises determining a weight for the SSD device based on the performance parameter of the SSD device. The method also comprises setting reserved space for the SSD device according to the weight for the SSD device, and the reserved space is inaccessible in the SSD device.

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: 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: 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.