Abstract: Various techniques are directed to a storage management method, an electronic device and a computer readable medium. Such techniques may involve: receiving a request for a target storage block in a disk; obtaining, from a cache, a cache indicator indicating a state of a group of storage blocks including the target storage block, the number of bits occupied by the cache indicator in the cache being less than the number of storage blocks in the group of storage blocks; and responding to the request based on the cache indicator. Such techniques can reduce times of access to the disk and thereby enhancing input/output performance.

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: A method and system for managing a storage system, the method comprising: creating a storage system including a first number of stripes, wherein each of the first number of stripes includes a second number of extents, and each of the second number of extents is distributed over a different storage device in a group of storage devices; with respect to a stripe among the first number of stripes, generating stripe information descriptive of a mapping relation between the second number of extents included in the stripe and the different storage devices in the group of storage devices; and with respect to a storage device where an extent among the second number of extents is located, building extent information about a mapping relation between an extent in the storage device and the stripe. In one embodiment of the present invention, there is provided a corresponding device and system.

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: Techniques manage a storage system. Such techniques involve: determining an expected input/output (I/O) concurrency number of an access request for a storage system, the access request being associated with a first one of a plurality of redundant arrays of independent disks (RAIDs) comprised in the storage system; in response to a current available I/O concurrency number of the first RAID being less than the expected I/O concurrency number, increasing the available I/O concurrency number of the first RAID based on a reserved I/O concurrency number of the storage system; and performing the access request using the first RAID having the increased available I/O concurrency number.

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: Implementations of the subject matter described herein provide a storage management method and system. The storage management method comprises: in response to receiving a write request, dividing data to be written into a plurality of data blocks with a predetermined size, the plurality of data blocks having their respective logic block addresses; evenly mapping, based on the logic block addresses, the plurality of data blocks to a plurality of RAID extents of a Redundant Array of Independent Disks (RAID); mapping the plurality of data blocks in the plurality of RAID extents to the disk, so that the plurality of data blocks are distributed in order of size of logic block addresses in the disk.

Abstract: In response to receiving a read request for target data, an external address of the target data is obtained from the read request, which is an address unmapped to a storage system; hit information of the target data in cache of the storage system is determined based on the external address; and based on the hit information, an address from the external address and an internal address for providing the target data is determined. The internal address is determined based on the external address and a mapping relationship. Therefore, it can shorten the data access path, accelerate the responding speed for the data access request, and allow the cache to prefetch the data more efficiently.

Abstract: A technique involves: in response to a stripe being created in a Redundant Array of Independent Disks (RAID), allocating to the stripe a storage space for storing a predetermined number of mapping information elements; creating one or more mapping information elements for the stripe; storing the one or more mapping information elements in the storage space; allocating respective storage sequence numbers to the one or more mapping information elements stored in the storage space; and in response to receiving an I/O request for the stripe indicating one of the respective storage sequence numbers, accessing the stripe based on the mapping information element in the storage space that is corresponding to the storage sequence number indicated by the I/O request. Such a technique can facilitate when disks encounter “glitch issues” simultaneously under extreme situations and effectively improve I/O read and write performance of a storage system.

Abstract: Techniques providing I/O control involve: in response to receiving an I/O request, detecting a first set bits for a stripe in a RAID. The RAID is built on disk slices divided from disks. The stripes include extents. Each of the first set bits indicates whether a disk slice where a corresponding extent in the stripe is located is in a failure state. The techniques further involve determining, from the stripe and based on the first set bits, a first set of extents in the failure state and a second set of extents out of the failure state. The techniques further involve executing the I/O request on the second set of extents without executing the I/O request on the first set of extents. Such techniques can simplify storage bits in I/O control, support the degraded stripe write request for the RAID and enhance performance executing the I/O control.

Abstract: Techniques manage a storage device. Such techniques involve: in response to receiving an I/O request for a storage device comprising a plurality of disks, determining, from the plurality of disks, at least one disk related to the I/O request; allocating, to each of the at least one disk, at least one access credit for completing the I/O request from total access credits of the disk, wherein the total access credits are associated with at least one of a type of the disk, a type of the I/O request and performance of the disk; and in response to respective access credits being allocated to the at least one disk, performing access requested by the I/O request to each of the at least one disk. Such techniques can effectively improve the overall access performance of the storage device.

Abstract: Techniques perform data storage. Such techniques may involve writing metadata to a first cache of a first processor, the metadata indicating allocation of a storage resource to user data. Such techniques may further involve determining an address range of the metadata in the first cache. Such techniques may further involve copying only data stored in the address range in the first cache to a second cache of a second processor. Accordingly, the data transmission volume between two processors is reduced, which helps to improve the overall performance of a storage system.

Abstract: Techniques manage a redundant array of independent disks. The techniques involve: in response to receiving a first command for assigning a first RAID stripe to a RAID group, storing metadata information of the first RAID stripe in a cache, the cache having different input/output (I/O) performance from the RAID; and storing the first command and the metadata information of the first RAID stripe in a predetermined storage space of the RAID in a sequential storage structure.

Abstract: Techniques manage a redundant array of independent disks. In such a technique, a response time of a first storage device in the RAID is compared to a first threshold. In response to the response time of the first storage device exceeding the first threshold, the first storage device is configured as a pseudo-degraded storage device, such that the pseudo-degraded storage device is responsive to write requests only.

Abstract: Techniques manage data of a Redundant Array of Independent Disks (RAID). Such techniques involve: obtaining a first parity of checksum pair, which is determined based on a first checksum when user data of data disks in the RAID are predetermined values; determining, based on current checksums of the data disks in the RAID, a second parity of checksum pair of the RAID, the first parity of checksum pair and the second parity of checksum pair respectively comprising a row parity of checksum and a diagonal parity of checksum; and determining, based on the first parity of checksum pair and the second parity of checksum pair, a third parity of checksum pair for updating parity data of parity disks of the RAID.

Abstract: A method and system for managing a storage system, the method comprising: creating a storage system including a first number of stripes, wherein each of the first number of stripes includes a second number of extents, and each of the second number of extents is distributed over a different storage device in a group of storage devices; with respect to a stripe among the first number of stripes, generating stripe information descriptive of a mapping relation between the second number of extents included in the stripe and the different storage devices in the group of storage devices; and with respect to a storage device where an extent among the second number of extents is located, building extent information about a mapping relation between an extent in the storage device and the stripe. In one embodiment of the present invention, there is provided a corresponding device and system.

Abstract: Implementations of the subject matter described herein provide a storage management method and system. The storage management method comprises: in response to receiving a write request, dividing data to be written into a plurality of data blocks with a predetermined size, the plurality of data blocks having their respective logic block addresses; evenly mapping, based on the logic block addresses, the plurality of data blocks to a plurality of RAID extents of a Redundant Array of Independent Disks (RAID); mapping the plurality of data blocks in the plurality of RAID extents to the disk, so that the plurality of data blocks are distributed in order of size of logic block addresses in the disk.

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: 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.

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), determining a stripe of the RAID related to the I/O request; determining metadata corresponding to the stripe, the metadata indicating validity of current data in a corresponding data block of the RAID, the data block comprising one or more stripes; in response to the metadata indicating that the current data is valid, executing the I/O request by accessing the RAID; and in response to the metadata indicating that the current data is invalid, responding to the I/O request with zero data as the current data. Accordingly, disk access is reduced, metadata cache efficiency is increased, I/O performance is improved and the RAID reliability is enhanced.