Abstract: In at least embodiment, processing can include: receiving virtual utilizations (VUs) for resources consumed in connection with recording entries in a log for commands or operations, wherein each resource has a corresponding VU which denotes a number of allocated units of the resource associated with entries of the log which have not been flushed from the log; determining a first resource having a maximum VU with respect to VUs of consumed resources; determining whether the maximum VU is within an acceptable VU range, wherein the acceptable VU range has bounds determined in accordance with a maximum deviation threshold associated with the first resource; and responsive to determining the maximum VU is not within the acceptable VU range of the first resource, performing one of a plurality of regulation actions that varies an amount of a system resource to accordingly vary a flush rate of entries from the log.

Abstract: A method, computer program product, and computing system for assigning flush ownership for a plurality of containers of a common frozen flushing work set to a storage processor of a pair of storage processors of a storage system. For each container of the plurality of containers of the common frozen flushing work set not assigned to a particular storage processor, the storage space of the container not assigned to the particular storage processor is reclaimed. For each container of the plurality of containers of the common frozen flushing work set assigned to a particular storage processor, data stored in the container assigned to the particular storage processor is flushed to persistent memory of the storage system.

Abstract: Techniques lock a storage area in a storage system including a first storage node and a second storage node. Such techniques involve adjusting a value of at least one of a first counter at the first node and a second counter at the second node in response to receiving a data access request for the storage area at at least one of the first node and the second node. Such techniques further involve allocating a lock flag to the first node in response to a ratio of the value of the first counter to the value of the second counter being greater than a first threshold, the lock flag indicating that the storage area is locked by the first node. Accordingly, storage resources required by nodes that are accessed more frequently in statistics are effectively reduced, and the efficiency of applying stripe lock reduction are improved.

Abstract: A method, computer program product, and computing system for processing, using a storage node, one or more updates to one or more metadata pages of a multi-node storage system. The one or more updates may be stored in one or more data containers in a cache memory system of the storage node, thus defining an active working set of data containers. Flushing ownership for each data container of the active working set may be assigned to one of the storage nodes based upon an assigned flushing ownership for each data container of a frozen working set and a number of updates within the frozen working set processed by each storage node, thus defining an assigned flushing storage node for each data container of the active working set. The one or more updates may be flushed, using the assigned flushing storage node, to a storage array.

Abstract: A method, computer program product, and computing system for executing a plurality of IO traces on a storage system. At least one vertical flow and at least one horizontal flow associated with the at least one vertical flow may be defined for the plurality of IO traces. A hierarchical representation of the plurality of IO traces may be generated with the at least one vertical flow and the at least one horizontal flow associated with the at least one vertical flow defined for the plurality of IO traces.

Abstract: Techniques for data recovery involve: reading target data corresponding to a first logical block from a first data block of a stripe of a RAID system, the target data being a compressed version of data in the first logical block; in accordance with a determination that an error occurs in the target data, reading data from a plurality of second data blocks of the stripe and first parity information from a first parity block of the stripe; comparing respective checksums of the data read from the plurality of second data blocks with a first predetermined checksum and a checksum of the first parity information with a second predetermined checksum; and determining recoverability of the target data based on a result of the comparison. Accordingly, it is possible to simplify the data recovery process, reduce the calculation and time costs in the data recovery, and improve the data recovery efficiency.

Abstract: In creating an extent array in a storage system, in response to receiving a request to generate an extent array using idle extents in storage devices, a width of an extent stripe is determined, and a size of the extent array is designated by the storage system. A first extent group and a second extent group are respectively selected from the storage devices based on the width to form a first extent stripe and a second extent stripe, and a first extent at a given position in the first extent group and a second extent at a given position in the second extent group are respectively located in different storage devices. Based on the first extent stripe and the second extent stripe, an address mapping representing the extent array is generated. The address mapping includes association between extent identifiers of extents and extent indexes of the extents.

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 method, computer program product, and computing system for executing a plurality of IO traces on a storage system. At least one vertical flow and at least one horizontal flow associated with the at least one vertical flow may be defined for the plurality of IO traces. A hierarchical representation of the plurality of IO traces may be generated with the at least one vertical flow and the at least one horizontal flow associated with the at least one vertical flow defined for the plurality of IO traces.

Abstract: Techniques for managing data involve receiving a write request to write a data block into a first stripe in a disk array, the write request comprising a first storage address for storing the data block. The techniques further involve determining, based on the first storage address, a first group of disks related to a data portion of the first stripe and a second group of disks related to a parity portion of the first stripe. The techniques further involve, in response to a first disk in the first group of disks being unavailable, storing a data sub-block related to the first disk into a first parity portion of the parity portion such that the data block is stored in the first stripe, the first parity portion being located at a second disk in the second group of disks. The techniques further involve returning a response to the write request, the response comprising a first indication indicating a status of the disks in the disk array.

Abstract: A technique manages a computing system based on a client/server architecture. In particular, an address mapping of a storage system is managed. The address mapping includes an association between storage spaces in a plurality of storage devices in the storage system and a user of the storage system. A data access service is provided to a client associated with the user based on the address mapping. The client includes at least any one of a user data client for accessing user data associated with the user in the storage system and a control data client for accessing control data associated with the user. Based on a client/server architecture, a uniform management mode is provided for user data and control data, so that the storage system is managed more simply and effectively.

Abstract: Techniques for storage management involve: determining expected usage time of a first storage disk in a set of storage disks, at least a part of the set of storage disks being configured to form at least one redundant array of independent disks (RAID); moving data in a first storage block, associated with a first RAID in the at least one RAID, in the first storage disk to a second storage block in a second storage disk in the set of storage disks based on a determination that the expected usage time is less than a predetermined threshold value; and replacing the first storage block with the second storage block, so that the second storage block is associated with the first RAID. Based on this manner, the stability of a storage system can be improved.

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: 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 involve: writing, when a first disk for dirty page storage has a failure, a first target page description generated by a first node and associated with a first set of target dirty pages of the first node and a second set of target dirty pages of a second node to a first page description storage layer for the first node in a second disk; writing a second target page description generated by the second node and associated with the first set of target dirty pages and the second set of target dirty pages to a second page description storage layer for the second node in the second disk; and restoring, when the failure has been eliminated, the first set of target dirty pages and the second set of target dirty pages in the first disk based on at least one of the descriptions.

Abstract: In techniques for selecting a rebuild destination in a storage system, a failed stripe group associated with a failed extent group in a failed storage device among storage devices is detected. A group of normal storage devices other than the failed storage device is determined. Regarding a normal storage device in the group of normal storage devices, a first count for the normal storage device is obtained, the first count representing a number of failed stripes which are allowed to be rebuilt to the normal storage device in the failed stripe group. Based on the first count, a destination storage device is selected from the group of normal storage devices for rebuilding a failed stripe in the failed stripe group. During rebuild, a destination for rebuilding the failed stripe may be effectively selected, and extents in reserved space in the storage system may be more fully utilized.

Abstract: Techniques involve: writing, when a first disk for dirty page storage has a failure, a first target page description generated by a first node and associated with a first set of target dirty pages of the first node and a second set of target dirty pages of a second node to a first page description storage layer for the first node in a second disk; writing a second target page description generated by the second node and associated with the first set of target dirty pages and the second set of target dirty pages to a second page description storage layer for the second node in the second disk; and restoring, when the failure has been eliminated, the first set of target dirty pages and the second set of target dirty pages in the first disk based on at least one of the descriptions.

Abstract: Techniques involve: determining, according to a determination that a performance level of a target storage unit is lower than a threshold level, whether idle disk slices that can be used for reconstructing malfunctioning disk slices in the target storage unit exist in a slice pool; determining a priority of the target storage unit according to a determination that the idle disk slices do not exist; and selecting replacing disk slices for reconstructing the malfunctioning disk slices from available storage units based at least in part on the priority, wherein the available storage units have performance levels not lower than the threshold level. In this way, data loss due to the off-line of storage units is prevented; and meanwhile, the performance of the entire storage system can be globally stabilized.

Abstract: Techniques for storage management involve: in response to a first disk becoming offline and remaining offline until a first time point, selecting a second storage slice in a second disk as a backup storage slice for a first storage slice in the first disk, the first storage slice being one of slices forming a redundant array of independent disks (RAID), the slices being located in different disks. The techniques further involve: writing, between the first time point and a second time point, data to be written into the first storage slice in the RAID to the second storage slice, the second time point being later than the first time point. The techniques further involve: in response to the first disk remaining offline until the second time point, replacing the first storage slice in the RAID with the second storage slice. Such techniques may improve performance of a RAID-based storage system.

Abstract: Techniques involve: determining a source disk slice from a plurality of disk slices of a plurality of storage arrays providing redundant storage, target data on the source disk slice needing to be removed; determining a destination disk slice for storing the target data needing to be removed from the source disk slice, a destination disk where the destination disk slice is located being different from a source disk where the source disk slice is located; and moving the target data from the source disk slice to the destination disk slice. Accordingly, such techniques can improve efficiency of a storage system.