Abstract: A processor, operable in a computing storage environment, allocates portions of a Scatter Index Table (SIT) disproportionately between a larger portion dedicated for meta data tracks, and a smaller portion dedicated for user data tracks, and processes a storage operation through the disproportionately allocated portions of the SIT using an allocated number of Task Control Blocks (TCB).

Abstract: For cache/data management in a computing storage environment, incoming data segments into a Non Volatile Storage (NVS) device of the computing storage environment are validated against a bitmap to determine if the incoming data segments are currently in use. Those of the incoming data segments determined to be currently in use are designated to the computing storage environment to protect data integrity.

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 processor, operable in a computing storage environment, for each rank in a storage management device in the computing storage environment, allocates a lower maximum count, and a higher maximum count, of Task Control Blocks (TCBs) to be implemented for performing a storage operation, and performs the storage operation using up to the lower maximum count of TCBs, yet only allows those TCBs above the lower maximum count to be allocated for performing the storage operation satisfying at least one criterion.

Abstract: Provided are a computer program product, system, and method for caching data in a storage system having multiple caches. A sequential access storage device includes a sequential access storage medium and a non-volatile storage device integrated in the sequential access storage device, received modified tracks are cached in the non-volatile storage device, wherein the non-volatile storage device is a faster access device than the sequential access storage medium. A spatial index indicates the modified tracks in the non-volatile storage device in an ordering based on their physical location in the sequential access storage medium. The modified tracks are destaged from the non-volatile storage device by comparing a current position of a write head to physical locations of the modified tracks on the sequential access storage medium indicated in the spatial index to select a modified track to destage from the non-volatile storage device to the storage device.

Abstract: Provided are a computer program product, system, and method for replicating tracks from a first storage to a second and third storages. A determination is made of a track in the first storage to transfer to the second storage as part of a point-in-time copy relationship and of a stride of tracks including the target track. The stride of tracks including the target track is staged from the first storage to a cache according to the point-in-time copy relationship. The staged stride is destaged from the cache to the second storage. The stride in the cache is transferred to the third storage as part of a mirror copy relationship. The stride of tracks in the cache is demoted in response to destaging the stride of the tracks in the cache to the second storage and transferring the stride of tracks in the cache to the third storage.

Abstract: Provided are a computer program product, system, and method for replicating tracks from a first storage to a second and third storages. A determination is made of a track in the first storage to transfer to the second storage as part of a point-in-time copy relationship and of a stride of tracks including the target track. The stride of tracks including the target track is staged from the first storage to a cache according to the point-in-time copy relationship. The staged stride is destaged from the cache to the second storage. The stride in the cache is transferred to the third storage as part of a mirror copy relationship. The stride of tracks in the cache is demoted in response to destaging the stride of the tracks in the cache to the second storage and transferring the stride of tracks in the cache to the third storage.

Abstract: A computational device maintains a first type of cache and a second type of cache. The computational device receives a command from the host to release space. The computational device synchronously discards tracks from the first type of cache, and asynchronously discards tracks from the second type of cache.

Abstract: A controller receives a request to perform staging or destaging operations with respect to an area of a cache. A determination is made as to whether one or more discard scans are being performed or queued for the area of the cache. In response to determining that one or more discard scans are being performed or queued for the area of the cache, the controller avoids satisfying the request to perform the staging or the destaging operations or a read hit with respect to the area of the cache.

Abstract: A controller receives a request to perform a release space operation. A determination is made that a new discard scan has to be performed on a cache, in response to the received request to perform the release space operation. A determination is made as to how many task control blocks are to be allocated to the perform the new discard scan, based on how many task control blocks have already been allocated for performing one or more discard scans that are already in progress.

Abstract: For facilitating data compression, a set of logical extents, each having compressed logical tracks of data, is mapped to a head physical extent and, if the head physical extent is determined to have been filled, to at least one overflow extent having spatial proximity to the head physical extent. Pursuant to at least one subsequent write operation and destage operation, the at least one subsequent write operation and destage operation determined to be associated with the head physical extent, the write operation is mapped to one of the head physical extent, the at least one overflow extent, and an additional extent having spatial proximity to the at least one overflow extent.

Abstract: A system includes a cache and a processor coupled to the cache. The cache stores data in multiple storage tracks and each storage track includes an associated multi-bit counter. The processor is configured to perform the following method. One method includes writing data to the plurality of storage tracks and incrementing the multi-bit counter on each respective storage track a predetermined amount each time the processor writes to a respective storage track. The method further includes scan each of the storage tracks in each of multiple scan cycles, decrementing each multi-bit counter each scan cycle, and destaging each storage track including a zero count. Also provided are physical computer storage mediums including a computer program product for performing the above method.

Abstract: A system includes a cache partitioned into multiple ranks configured to store multiple storage tracks and a processor coupled to the cache. The processor is configured to perform the following method. One method includes allocating an amount of storage space in the cache to each rank and monitoring a current amount of storage space used by each rank with respect to the amount of storage space allocated to each respective rank. The method further includes destaging storage tracks from each rank until the current amount of storage space used by each respective rank is equal to a predetermined minimum amount of storage space with respect to the amount of storage space allocated to each rank. Also provided are physical computer storage mediums including code that, when executed by a processor, cause the processor to perform the above method.

Abstract: For efficient track destage in secondary storage in a more effective manner, for temporal bits employed with sequential bits for controlling the timing for destaging the track in a primary storage, the temporal bits and sequential bits are transferred from the primary storage to the secondary storage. The temporal bits are allowed to age on the secondary storage.

Abstract: A system includes a write cache configured to store a plurality of storage tracks and configured to be coupled to one or more hosts, and a processor coupled to the write cache. The processor includes code that, when executed by the processor, causes the processor to perform the method below. One method includes monitoring the write cache for write operations from the host(s) and determining if the host(s) is/are idle based on monitoring the write cache for write operations from the host(s). The storage tracks are destaged from the write cache if the host(s) is/are idle and are not destaged from the write cache if one or more of the hosts is/are not idle. Also provided are physical computer storage mediums including a computer program product for performing the above method.

Abstract: A point-in-time copy relationship associates tracks in a source storage with tracks in a target storage. The target storage stores the tracks in the source storage as of a point-in-time. A write request is received including an updated source track for a point-in-time source track in the source storage in the point-in-time copy relationship. The point-in-time source track was in the source storage at the point-in-time the copy relationship was established. The updated source track is stored in a first cache device. A prefetch request is sent to the source storage to prefetch the point-in-time source track in the source storage subject to the write request to a second cache device. A read request is generated to read the source track in the source storage following the sending of the prefetch request. The read source track is copied to a corresponding target track in the target storage.

Abstract: A controller receives a request to perform a release space operation. A determination is made that a new discard scan has to be performed on a cache, in response to the received request to perform the release space operation. A determination is made as to how many task control blocks are to be allocated to the perform the new discard scan, based on how many task control blocks have already been allocated for performing one or more discard scans that are already in progress.

Abstract: Provided are a computer program product, sequential access storage device, and method for managing data in a sequential access storage device receiving read requests and write requests from a system with respect to tracks stored in a sequential access storage medium. A prefetch request indicates prefetch tracks in the sequential access storage medium to read from the sequential access storage medium. The accessed prefetch tracks are cached in a non-volatile storage device integrated with the sequential access storage device, wherein the non-volatile storage device is a faster access device than the sequential access storage medium. A read request is received for the prefetch tracks following the caching of the prefetch tracks, wherein the prefetch request is designated to be processed at a lower priority than the read request with respect to the sequential access storage medium. The prefetch tracks are returned from the non-volatile storage device to the read request.

Abstract: A system includes a cache and a processor. The processor is configured to utilize a first thread to continually determine a desired scan time for scanning the plurality of storage tracks in the cache and utilize a second thread to continually control an actual scan time of the plurality of storage tracks in the cache based on the continually determined desired scan time. One method includes utilizing a first thread to continually determine a desired scan time for scanning the plurality of storage tracks in the cache and utilizing a second thread to continually control an actual scan time of the plurality of storage tracks in the cache based on the continually determined desired scan time.

Abstract: A mechanism is provided in a storage device for performing a write operation. The mechanism configures a write buffer memory with a plurality of write buffer portions. Each write buffer portion is dedicated to a predetermined block size category within a plurality of block size categories. For each write operation from an initiator, the mechanism determines a block size category of the write operation. The mechanism performs each write operation by writing to a write buffer portion within the plurality of write buffer portions corresponding to the block size category of the write operation.