Abstract: Techniques for managing metadata storage units involve: in response to receiving, from a client, a request for allocating a target number of metadata storage units, determining a first number of available metadata storage units remaining in a metadata storage space of a storage system after the allocation is performed; and if the first number is not less than a reserved number, allocating the target number of metadata storage units from the metadata storage space for the client to use, wherein the reserved number is associated with a usage condition of the metadata storage units in the storage system. Accordingly, such techniques can effectively manage metadata and improve the performance of a system.

Abstract: A method, computer program product, and computing system for defining one or more user data portions and at least two reserved portions of a solid-state drive (SSD). An operating mode of the SSD may be determined. One or more of the at least two reserved portions of the SSD may be utilized based upon, at least in part, the operating mode of the SSD.

Abstract: The present disclosure relates to a method, a device, and a computer program product for managing a storage system. The storage system includes a first control node, a second control node, and a persistent storage device, the first control node being in an activated state, and the second control node being in a state of transfer from a non-activated state to an activated state. A method includes: loading a first list of page descriptors of the storage system to the second control node to generate a second list of page descriptors at the second control node, the first list including a portion of multiple page descriptors of the storage system that has been modified but has not been flushed to the persistent storage device; receiving a synchronization message from the first control node that indicates that the first list has been modified by the first control node; and updating the second list at the second control node based on the synchronization message.

Abstract: Data access techniques involve: determining whether there is a copy operation that is being performed from a first LU to a second LU in response to receiving a write operation request for a first data block in the first logic unit (LU); detecting a copy status of data in the first data block in response to determining that there is the copy operation that is being performed; and determining a processing strategy of the write operation request during execution of the copy operation based on the copy status.

Abstract: Techniques involve managing a storage system. In accordance with the techniques, a plurality of copies of metadata of the storage system are read from a plurality of storage devices in a resource pool of the storage system. The resource pool includes a first number of storage devices, and the metadata describes configuration information of the storage system. A second number of copies are selected from the plurality of copies based on version information in the plurality of copies, where the second number of copies comprises the metadata in the same version. It is determined whether a relation between the first number and the second number satisfies a predetermined condition. The second number of copies are identified as trusted metadata based on determining the relation satisfies the predetermined condition. With the foregoing example implementation, the metadata in the storage system may be managed with higher reliability.

Abstract: Techniques for managing metadata storage units involve: in response to receiving, from a client, a request for allocating a target number of metadata storage units, determining a first number of available metadata storage units remaining in a metadata storage space of a storage system after the allocation is performed; and if the first number is not less than a reserved number, allocating the target number of metadata storage units from the metadata storage space for the client to use, wherein the reserved number is associated with a usage condition of the metadata storage units in the storage system. Accordingly, such techniques can effectively manage metadata and improve the performance of a system.

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 rebuilding a disk array involve, in response to receiving a message for rebuilding disk arrays in a storage system, determining a target disk that causes rebuilding. Such techniques further involve determining from the disk arrays a set of disk arrays related to the target disk, and generating subsets of disk arrays from the set of disk arrays, each subset including disk arrays that can be rebuilt in parallel. Such techniques further involve determining, based on a number of disks included in each subset, a target subset from the plurality of subsets, and rebuilding disk arrays in the target subset in parallel. Accordingly, a disk array that is most suitable for parallel rebuilding may be determined, and the process of rebuilding the disk array is sped up. Such techniques reduce the delay caused by performing rebuilding, and improve rebuilding efficiency.

Abstract: The present disclosure relates to a method, a device, and a computer program product for managing a storage system. The storage system includes a first control node, a second control node, and a persistent storage device, the first control node being in an activated state, and the second control node being in a state of transfer from a non-activated state to an activated state. A method includes: loading a first list of page descriptors of the storage system to the second control node to generate a second list of page descriptors at the second control node, the first list including a portion of multiple page descriptors of the storage system that has been modified but has not been flushed to the persistent storage device; receiving a synchronization message from the first control node that indicates that the first list has been modified by the first control node; and updating the second list at the second control node based on the synchronization message.

Abstract: Techniques involve: in response to adding a second set of disks into a redundant array of independent disks (RAID) including a first set of disks and a total number of disks in the first and second sets exceeding a predetermined threshold, determining types and numbers of disks in the first and second sets, respectively; determining, based on the types and numbers of the disks determined and a performance indicator of the RAID having the added second set, respective types and numbers of disks comprised in a plurality of sets to which the disks in the RAID are to be allocated; and performing, based on the type and number of disks in the first set and the respective types and numbers of disks, an allocation of a disk in the first set to one of the plurality of sets, until all the disks in the first set have been allocated.

Abstract: A method performed by a computing device having memory is provided. The method includes (a) detecting corruption in a first page description block (PDB) of a plurality of PDBs stored in sequence in the memory, each PDB storing a set of page descriptors (PDs) that point to pages of data sequentially stored in the memory that are part of a single transaction, PDBs that represent the same transaction being contiguous within the sequence; (b) searching for a second PDB of the plurality of PDBs, the second PDB satisfying the following criteria: (1) it is not corrupted, and (2) it represents a same transaction as the first PDB; and (c) reconstructing the first PDB using the second PDB. An apparatus, system, and computer program product for performing a similar method are also provided.

Abstract: Techniques process and manage a storage unit access. In accordance with such a technique, a data access request which is from a host system and for a first storage unit in the first storage system is received, wherein the first storage unit is a secondary storage unit; and the data access request is forwarded to a second storage unit in a second storage system associated with the first storage unit via a redirection link from the first storage system to the second storage system, wherein the second storage unit is a primary storage unit. Through such techniques, the host system can be allowed to send a data access request for the secondary storage unit, so that the host system does not need to resend the data access request, thereby reducing delay and interruption caused by such requests.

Abstract: Techniques manage metadata. Such techniques involve: in response to receiving a request for accessing metadata in a first page, determining, from a plurality of storage units including pages for storing metadata, a storage unit where the first page is located, the plurality of storage units including a first storage unit and a second storage unit, an access speed of the second storage unit exceeding an access speed of the first storage unit; accessing, from the determined storage unit, the first page for metadata; in response to the first page being accessed from the first storage unit, determining whether hotness of the first page exceeds a threshold level; and in response to the hotness of the first page exceeding the threshold level, transferring the first page from the first storage unit to the second storage unit. Accordingly, such techniques can improve the efficiency for accessing the metadata.

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 manage a redundant array of independent disks. In such a technique, an instruction to expand the RAID is received, the RAID being formed by a first group of storage devices and including a first group of RAID extents. A second group of RAID extents created on a second group of storage devices and logical units are created on the second group of RAID extents. In response to receiving an indication for a failure of the creation of the second group of RAID extents or the logical units, a notification is generated for indicating a failure of the expansion of the RAID without triggering a shuffling operation, the shuffling operation causing storage extents in the first and second groups of RAID extents to be distributed in the first and second groups of storage devices.

Abstract: Techniques for rebuilding a disk array involve, in response to receiving a message for rebuilding disk arrays in a storage system, determining a target disk that causes rebuilding. Such techniques further involve determining from the disk arrays a set of disk arrays related to the target disk, and generating subsets of disk arrays from the set of disk arrays, each subset including disk arrays that can be rebuilt in parallel. Such techniques further involve determining, based on a number of disks included in each subset, a target subset from the plurality of subsets, and rebuilding disk arrays in the target subset in parallel. Accordingly, a disk array that is most suitable for parallel rebuilding may be determined, and the process of rebuilding the disk array is sped up. Such techniques reduce the delay caused by performing rebuilding, and improve rebuilding efficiency.

Abstract: Techniques manage metadata. Such techniques involve: in response to receiving a request for accessing metadata in a first page, determining, from a plurality of storage units including pages for storing metadata, a storage unit where the first page is located, the plurality of storage units including a first storage unit and a second storage unit, an access speed of the second storage unit exceeding an access speed of the first storage unit; accessing, from the determined storage unit, the first page for metadata; in response to the first page being accessed from the first storage unit, determining whether hotness of the first page exceeds a threshold level; and in response to the hotness of the first page exceeding the threshold level, transferring the first page from the first storage unit to the second storage unit. Accordingly, such techniques can improve the efficiency for accessing the metadata.

Abstract: Techniques involve: in response to adding a second set of disks into a redundant array of independent disks (RAID) including a first set of disks and a total number of disks in the first and second sets exceeding a predetermined threshold, determining types and numbers of disks in the first and second sets, respectively; determining, based on the types and numbers of the disks determined and a performance indicator of the RAID having the added second set, respective types and numbers of disks comprised in a plurality of sets to which the disks in the RAID are to be allocated; and performing, based on the type and number of disks in the first set and the respective types and numbers of disks, an allocation of a disk in the first set to one of the plurality of sets, until all the disks in the first set have been allocated.

Abstract: Techniques involve managing a storage system. In accordance with the techniques, a plurality of copies of metadata of the storage system are read from a plurality of storage devices in a resource pool of the storage system. The resource pool includes a first number of storage devices, and the metadata describes configuration information of the storage system. A second number of copies are selected from the plurality of copies based on version information in the plurality of copies, where the second number of copies comprises the metadata in the same version. It is determined whether a relation between the first number and the second number satisfies a predetermined condition. The second number of copies are identified as trusted metadata based on determining the relation satisfies the predetermined condition. With the foregoing example implementation, the metadata in the storage system may be managed with higher reliability.

Abstract: Data access techniques involve: determining whether there is a copy operation that is being performed from a first LU to a second LU in response to receiving a write operation request for a first data block in the first logic unit (LU); detecting a copy status of data in the first data block in response to determining that there is the copy operation that is being performed; and determining a processing strategy of the write operation request during execution of the copy operation based on the copy status.