Abstract: For a plurality of input/output (I/O) operations waiting to assemble complete data tracks from data segments, a process, separate from a process responsible for the data assembly into the complete data tracks, is initiated for waking a predetermined number of the waiting I/O operations. A total number of I/O operations to be awoken at each of an iterated instance of the waking is limited.

Abstract: Data operations, requiring a lock, are batched into a set of operations to be performed on a per-core basis. A global lock for the set of operations is periodically acquired, the set of operations is performed, and the global lock is freed so as to avoid excessive duty cycling of lock and unlock operations in the computing storage environment.

Abstract: A set of like tasks to be performed is organized into a first group. Upon a determined imbalance between dispatch queue depths greater than a predetermined threshold, the set of like tasks is reassigned to an additional group.

Abstract: A method for deleting a relation between a source and a target in a multi-target architecture is described. The multi-target architecture includes a source and multiple targets mapped thereto. In one embodiment, such a method includes initially identifying a relation for deletion from the multi-target architecture. A target associated with the relation is then identified. The method then identifies a sibling target that inherits data from the target. Once the target and the sibling target are identified, the method copies the data from the target to the sibling target. The relation between the source and the target is then deleted. A corresponding computer program product is also disclosed and claimed herein.

Abstract: A computational device allocates a plurality of solid state disks to a plurality of redundant array of independent disk (RAID) ranks, wherein a different solid state disk is absent in each RAID rank of the plurality of RAID ranks. The computational device determines at least one selected solid state disk from the plurality of solid state disks, wherein the at least one selected solid state disk is estimated to have undergone a greater amount of wear in comparison to other solid state disks in the plurality of solid state disks. Relatively more data and parity information is written to those RAID ranks in which the at least one selected solid state disk is absent in comparison to those RAID ranks in which the at least one selected solid state disk is present.

Abstract: Provided are a method, system, and article of manufacture for validating stored copies of data images to load into memory. An image of data is maintained in a memory, wherein the image in the memory includes a generation number. The image in the memory is written to at least two copies of the image to storage locations in response to a first event, wherein the generation number for the image in the memory is stored in the storage locations having the copies of the image. A check generation number is stored in a storage location. The image is loaded from at least one of the copies of the image in one of the storage locations to the memory in response to a second event The generation number for the image loaded into the memory. The check generation number is incremented in response to the second event. The generation numbers for the copies of the image in the storage locations and the check generation number are used to validate the copies of the image.

Abstract: A method for providing rolling continuous data protection of source data is disclosed. In one embodiment, such a method includes enabling a user to select source data and establish a first interval when point-in-time copies of the source data are generated. The method further enables the user to specify a first number of point-in-time copies to retain at the first interval. The method further enables the user to specify a second number of point-in-time copies to retain at a second interval, wherein the second interval is a (n?2) multiple of the first interval. The method further enables the user to specify a third number of point-in-time copies to retain at a third interval, wherein the third interval is a (n?2) multiple of the second interval. A corresponding apparatus and computer program product are also disclosed.

Abstract: Provided are a method, system and article of manufacture, wherein a first application executes at least two threads corresponding to a simultaneous multi-threaded processor whose resources have been acquired by the first application. The at least two threads are synchronized before releasing the simultaneous multi-threaded processor to a second application.

Abstract: A method to maintain write operation atomicity where a write operation crosses a data storage medium track boundary. The method supplies a storage controller comprising a host adapter, a processor, and a NVS. The host adapter receives from a host computer a write request and data. The method determines if the write request will cross a data storage medium track boundary. If the write request will cross a data storage medium track boundary, the method indicates to the host adapter that the write request comprises a two-track transfer, and writes the data to the NVS as the data is received. If the host computer fails prior to providing all the data to the storage controller, the method discards the data written to the NVS to ensure write operation atomicity.

Abstract: Provided are a method, system, and article of manufacture for maintaining information of a relationship of target volumes comprising logical copies of a source volume. Information is maintained on a source volume having a plurality of data units and a plurality of target volumes created at different points-in-time maintaining a logical copy of the data units in the source volume for the different points-in-time. A source downstream pointer is generated for each data unit in the source volume to point to a corresponding data unit in a first target volume. For each target volume data unit whose data is maintained in the source volume or another one of the target volumes, a first upstream pointer is generated indicating one of the source and target volumes from which the target volume data unit inherits data.

Abstract: An apparatus and program storage device for maintaining data is provided that includes receiving primary data at a first node, receiving mirrored data from a second and third node at the first node, and mirroring data received at the first node to a second and third node.

Abstract: An apparatus, system, and method are disclosed for storing and retrieving compressed data. A compression module compresses a data file organized in logical tracks. A ratio module determines a track compression ratio. The track compression ratio is a ratio of an integer value n to one. A destage module destages a single directory entry for the data file to a directory. The directory entry points to a zeroth track on a hard disk drive. The destage module further destages the data file sequentially to tracks of the hard disk drive from the zeroth track with n logical tracks of the data file stored on one physical track of the hard disk drive. A stage module stages a kth logical track from a physical track of the hard disk drive. The physical track is specified by an integer value of k divided by n.

Abstract: Provided are a method, system, and article of manufacture for determining whether to use a repository to store data updated during a resynchronization. Writes to a primary storage are transferred to a secondary storage. A logical copy of the secondary storage as of a point-in-time is established. Writes to the secondary storage in the logical copy received from the primary storage during a logical copy duration after the point-in-time are stored in a repository that comprises less storage space than the secondary storage in the logical copy. The transferring of writes to the secondary storage is suspended. During the suspension writes to the primary storage are indicated in an out-of-synch data structure.

Abstract: Provided are a method, system, and article of manufacture for validating stored copies of data images to load into memory. An image of data is maintained in a memory, wherein the image in the memory includes a generation number. The image in the memory is written to at least two copies of the image to storage locations in response to a first event, wherein the generation number for the image in the memory is stored in the storage locations having the copies of the image. A check generation number is stored in a storage location. The image is loaded from at least one of the copies of the image in one of the storage locations to the memory in response to a second event. The generation number for the image loaded into the memory. The check generation number is incremented in response to the second event. The generation numbers for the copies of the image in the storage locations and the check generation number are used to validate the copies of the image.

Abstract: Provided are a method, system, and article of manufacture for validating stored copies of data images to load into memory. An image of data is maintained in a memory, wherein the image in the memory includes a generation number. The image in the memory is written to at least two copies of the image to storage locations in response to a first event, wherein the generation number for the image in the memory is stored in the storage locations having the copies of the image. A check generation number is stored in a storage location. The image is loaded from at least one of the copies of the image in one of the storage locations to the memory in response to a second event The generation number for the image loaded into the memory. The check generation number is incremented in response to the second event. The generation numbers for the copies of the image in the storage locations and the check generation number are used to validate the copies of the image.

Abstract: Embodiments of the disclosure relate to archiving data in a storage system. An exemplary embodiment comprises making a flash copy of data in a source volume, compressing data in the flash copy wherein each track of data is compressed into a set of data pages, and storing the compressed data pages in a target volume. Data extents for the target volume may be allocated from a pool of compressed data extents. After each stride worth of data is compressed and stored in the target volume, data may be destaged to avoid destage penalties. Data from the target volume may be decompressed from a flash copy of the target volume in a reverse process to restore each data track, when the archived data is needed. Data may be compressed and uncompressed using a Lempel-Ziv-Welch process.

Abstract: Provided are a method, system, and article of manufacture for using different algorithms to destage different types of data from cache. A first destaging algorithm is used to destage a first type of data to a storage for a first duration. A second destaging algorithm is used to destage a second type of data to the storage for a second duration.

Abstract: A method for allocating space in a cache based on media I/O speed is disclosed herein. In certain embodiments, such a method may include storing, in a read cache, cache entries associated with faster-responding storage devices and cache entries associated with slower-responding storage devices. The method may further include implementing an eviction policy in the read cache. This eviction policy may include demoting, from the read cache, the cache entries of faster-responding storage devices faster than the cache entries of slower-responding storage devices, all other variables being equal. In certain embodiments, the eviction policy may further include demoting, from the read cache, cache entries having a lower read-hit ratio faster than cache entries having a higher read-hit ratio, all other variables being equal. A corresponding computer program product and apparatus are also disclosed and claimed herein.

Abstract: Provided are a method, system, and program for an adaptor to read and write to system memory. A plurality of blocks of data to write to storage are received at an adaptor. The blocks of data are added to a buffer in the adaptor. A determination is made of pages in a memory device and I/O requests are generated to write the blocks in the buffer to the determined pages, wherein two I/O requests are generated to write to one block split between two pages in the memory device. The adaptor executes the generated I/O requests to write the blocks in the buffer to the determined pages in the memory device.

Abstract: Provided are a method, system, and article of manufacture for determining whether to use a full volume or repository for a logical copy backup space. A determination is made of a source volume to backup using a logical copy operation. The logical copy operation is completed upon indicating the source volume data to backup. During a logical copy duration, point-in-time data in the source volume as of a point-in-time when the logical copy was established is copied to a backup space in response to receiving an update to the point-in-time data. A history of writes to the source volume is processed to determine whether to allocate a full target volume as the backup space providing a corresponding data unit for each data unit in the source volume or allocate a repository as the backup space, wherein the repository uses less storage space than the full target volume. The logical copy operation using the determined full target volume or repository as the backup space is initiated.