Abstract: The present invention discloses a method and device for managing a storage system. Specifically, in one embodiment of the present invention, there is proposed a method for managing a storage system, the storage system comprising a buffer device and a plurality of storage devices. The method comprises: receiving an access request with respect to the storage system; determining a storage device among the plurality of storage devices has been failed; and in response to the access request being an access request with respect to the failed storage device, serving the access request with data in the buffer device so as to reduce internal data access in the storage system. In one embodiment of the present invention, there is proposed a device for managing a storage system.

Abstract: A logical unit of non-volatile data storage is provided for persistently storing metadata. The logical unit is provided by allocating RAID (Redundant Array of Independent Disks) extents to the logical unit, and allocating logical block addresses for the logical unit from within a logical address space of the logical unit to store blocks of metadata written to the logical unit. In response to detecting that a stored indication of a last allocated logical block address for the logical unit has been lost, two RAID extents that were last allocated to the logical unit are identified, and a binary search is performed across logical block addresses within the two RAID extents that were last allocated to the logical unit to locate the last allocated logical block address for the logical unit within the logical address space of the logical unit.

Abstract: Techniques involve avoiding a potential failure event on a disk array. Along these lines, data collected for a disk array are obtained. It is determined, based on the collected data, whether a potential failure event is to occur on the disk array. In response to determining that the potential failure event is to occur on the disk array, an action to be taken for the disk array is determined, to avoid occurrence of the potential failure event.

Abstract: Techniques involve: determining, according to a received request for creating a stripe in a storage system, a type of the stripe; acquiring a first workload distribution corresponding to the determined type, wherein the first workload distribution describes the distribution, among a first number of storage devices, of multiple extents in a set of stripes of this type in the storage system; selecting a set of extents from the first number of storage devices based on the first workload distribution, so that the distribution, among the first number of storage devices, of the selected set of extents and the multiple extents in the set of stripes of this type satisfies a preset distribution condition associated with the type; and using the selected set of extents to create the requested stripe based on a stripe creation rule associated with the type. The stripes can be managed in a more effective manner.

Abstract: Techniques for storage management involve determining, in response to a detection that a disk changes from an unavailable state to an available state, at least one candidate storage unit associated with the disk; acquiring historical access information about the at least one candidate storage unit, the historical information comprising information related to a write request directed to the at least one candidate storage unit when the disk is in the unavailable state; determining a target storage unit from the at least one candidate storage unit based on the historical access information; and rebuilding the target storage unit. Such techniques may, in a low-cost manner, improve rebuilding efficiency and reliability of a storage system.

Abstract: A method of managing operation of a data storage system (DSS) is provided. The method includes (a) reserving space within a dedicated metadata storage region (DMSR); (b) in response to determining that accommodating a storage request requires use of the reserved space, entering a restricted write mode; (c) while operating in the restricted write mode, using the reserved space in a process that frees space within the DMSR outside the reserved space; and (d) exiting the restricted mode in response to freeing space within the DMSR outside the reserved space. An apparatus, system, and computer program product for performing a similar method are also provided.

Abstract: Techniques are directed to managing Redundant Array of Independent Disks (RAID) storage space. One technique involves providing, by RAID circuitry, a storage space request to mapper circuitry; receiving, by the RAID circuitry, a storage space reply from the mapper circuitry in response to the storage space request; and performing, by the RAID circuitry, a follow-up operation based on the storage space reply from the mapper circuitry. Another technique involves, receiving, by mapper circuitry, a storage space request from RAID circuitry; performing, by the mapper circuitry, a storage space management operation in response to the storage space request; and providing, by the mapper circuitry, a storage space reply to the RAID circuitry, the storage space reply identifying a result of the storage space management operation.

Abstract: Techniques for information update involve: updating, at a first node, first information in a first memory and second information associated with the first information, wherein the first information needs to be persistently stored, and the second information can be obtained from the first information and does not need to be stored persistently; storing the updated first information and the updated second information into a first region and a second region of a first persistent storage device, respectively; synchronizing the updated first information and the updated second information to a second node; and validating the updated first information stored in the first region and invalidating the updated second information stored in the second region based on a determination that the synchronization is successful. Such techniques can achieve incremental update of non-persistent information, thereby improving system performance.

Abstract: Techniques for generating merge-friendly sequential IO patterns in shared logger page descriptor (PD) tiers. The techniques can be employed in an active-active clustered system that includes a primary storage node, a secondary storage node, a logger shared between the primary and secondary storage nodes, and a storage device such as a non-volatile memory (NVM) device. The techniques can include allocating at least a first trunk and a second trunk in a shared PD tier of the logger, sequentially writing PD metadata and/or data by the primary storage node and the secondary storage node to the first trunk and the second trunk, respectively, merging the PD metadata/data units sequentially written to each respective trunk together to obtain PD metadata/data having an increased size up to the size of the respective trunks, and storing the merged PD metadata/data to the NVM device.

Abstract: Techniques involve: in response to receiving an access request for a logical address, determining a first virtual storage unit and a first offset within the first virtual storage unit corresponding to the logical address; determining a first set of virtual storage units to which the first virtual storage unit belongs and a position of the first virtual storage unit, determining, from the plurality of physical storage units corresponding to the first set of virtual storage units and based on the position and the first offset, a physical storage unit and a second offset within the physical storage unit corresponding to the logical address; and performing, based on an identifier of the physical storage unit and the second offset, a data access operation requested by the access request. Accordingly, I/O loads on a plurality of disks can be balanced, thereby improving overall performance of a storage system.

Abstract: Implementations of the present disclosure relate to method and device for managing a storage system. The method comprises in response to receiving a write request at a storage system, determining whether storage units allocated to a logic storage unit of the storage system are sufficient for data associated with the write request. The method also comprises in response to determining that the allocated storage units are insufficient, allocating a new storage unit to the logic storage unit. The method further comprises updating metadata associated with allocation of the storage units of the storage system, the metadata indicating a mapping between the logic storage unit and the storage units. The method also comprises encrypting the updated metadata. Other implementations of the present disclosure also involve corresponding method, device and computer-readable medium for decryption metadata and recovering the logic storage unit using the decrypted metadata.

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: 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: In a method and apparatus for storage management, a method includes: creating a plurality of profiles for address mapping, the profiles comprising a part of mapping relation in the total mapping table and creating an index for a part of the plurality of profiles to accelerate the lookup speed. A corresponding device and computer program product are also disclosed.

Abstract: A storage method and device for a solid-state drive is provided in embodiments of the present disclosure. The method includes: configuring a checkpoint drive and a cache drive; backing up data blocks from a data drive into the checkpoint drive; and in response to the data drives being corrupted, writing into a further data drive part of the data blocks backed up into the checkpoint drive and part of data blocks in the cache drive. The number of required SSD drives can be significantly reduced with the method and device without losing the data restoration capability. In addition, the degrading performance can also be maintained at a relatively high level.

Abstract: Techniques involve determining updated disk sets. The techniques further involve determining, from the updated disk sets, a target disk set for a storage unit associated with a plurality of storage disks. The techniques further involve determining position information of disk slices corresponding to the storage unit in the plurality of storage disks, in which the position information indicates respective updated disk sets in which the disk slices are located. The techniques further involve in accordance with a determination that an updated disk set indicated by position information of at least one of the disk slices is different from the target disk set, moving data in the at least one disk slice to the target disk set. Accordingly, an arrangement of a storage units across different disk sets can be avoided, and utilization rates of a plurality of storage disks can be made more uniform.

Abstract: A method, computer program product, and computer system for identifying, by a computing device, a pattern in a super block of a logger tier. It may be determined that the pattern in the super block of the logger tier is a known pattern, wherein the known pattern indicates invalid data in the logger tier. The logger tier may be booted up by storing an unknown pattern in the super block into the logger tier, wherein the unknown pattern indicates valid data in the logger tier.

Abstract: Aspects of the invention provide means for addressing layout retargeting shortfalls. Initially, an original design shape in the layout is allowed to be simulated by process simulation to form process simulation contours. A polygon is then fitted to the process simulation contours to form a fitted simulated shape. Subsequently, whether the fitted simulated shape differs from the original design shape is detected. The process simulation may reflect the changes to the layout that occur at a foundry as part of a retargeting process. Advantageously, addressing a layout for retargeting shortfalls in accordance with aspects of the invention is likely to result in manufactured semiconductor devices having higher yields and reliability than those produced from a like layout that is not addressed in this manner.

Abstract: Techniques manage addresses in a storage system. In such techniques, an address page of an address pointing to target data in the storage system is determined in response to receiving an access request for accessing data in the storage system. A transaction for managing the address page is generated on the basis of the address page, here the transaction at least comprises an indicator of the address page and a state of the transaction. A counter describing how many times the address page is referenced is set. The transaction is executed at a control node of the storage system on the basis of the counter. With such techniques, the access speed for addresses in the storage system can be accelerated, and then the overall response speed of the storage system can be increased.

Abstract: Techniques manage a storage system. Such techniques involve, in response to receiving a request to add a first number of disks to a storage resource pool in the storage system, determining whether the first number of disks are to be added to the storage resource pool in a plurality of phases. Such techniques further involve determining a second number of disks to be added to the storage resource pool in the first phase. Such techniques further involve determining first information on a first disk array group to be created with the second number of disks in the first phase. Such techniques further involve adding the second number of disks to the storage resource pool in the first phase by creating the first disk array group based on the first information. Such techniques enable a user to obtain an available capacity of the extended storage resource pool quickly and efficiently.