Abstract: A Write On Reference Mesh (WORM) detects a memory write operation to a reference location of a mesh entry in a memory window mesh and invokes an action responsive to the detected write. The mesh entries are laid out in zones. The invoked action is dependent on the individual mesh entry or the zone in which the write operation was detected. The action invoked can be configured by the custom logic provided by the vendor. Accordingly, in a special purpose processor, custom logic can trigger a wide variety of sophisticated actions by detecting a write operation to one of any number of specific memory addresses in the memory window.

Abstract: A storage controller uses a stripe-aligned metadata to describe data buffers in the storage controller's cache. A stripe buffer list and other metadata structures are aligned to stripe boundaries on storage media. Each stripe buffer list references data buffers in the cache memory of the storage controller that are dedicated to storing the data associated with a given disk stripe during a storage transaction. A stripe buffer descriptor table associates each stripe buffer list with the corresponding disk stripe through a virtual block address range and logical disk identifier. A stripe buffer list “present bits” table and a stripe buffer list “dirty bits” table maintain a record of the state of individual data buffers. With these metadata structures, data buffers in cache memory are effectively aligned with virtual disk stripes of the storage media, making for a simpler and more efficient storage transaction.

Abstract: In a data storage system a number of records are prefetched from large volume storage devices for transfer to a cache in order to return requested records to a host computer in response to a read request from the host computer. If a previous prefetch is not complete when the read request is received, the number of records in a next prefetch of records is increased by a preset amount. If a previous prefetch is complete, a next prefetch of records is initiated with the same number of records in the prefetch as the previous prefetch. The initiation of prefetch operations is triggered by detection of a sequential read stream in a plurality of read requests from the host computer. When the prefetch size is increased, the preset amount of the increase equals the number of records in the read request from the host computer. After requested records are returned from the cache to the host computer in response to the read request, storage space in the cache used by the returned requested records is released.

Abstract: In a data storage system a number of records are prefetched from large volume storage devices for transfer to a cache in order to return requested records to a host computer in response to a read request from the host computer. If a previous prefetch is not complete when the read request is received, the number of records in a next prefetch of records is increased by a preset amount. If a previous prefetch is complete, a next prefetch of records is initiated with the same number of records in the prefetch as the previous prefetch. The initiation of prefetch operations is triggered by detection of a sequential read stream in a plurality of read requests from the host computer. When the prefetch size is increased, the preset amount of the increase equals the number of records in the read request from the host computer. After requested records are returned from the cache to the host computer in response to the read request, storage space in the cache used by the returned requested records is released.

Abstract: In a data storage system a number of records are prefetched from large volume storage devices for transfer to a cache in order to return requested records to a host computer in response to a read request from the host computer. If a previous prefetch is not complete when the read request is received, the number of records in a next prefetch of records is increased by a preset amount. If a previous prefetch is complete, a next prefetch of records is initiated with the same number of records in the prefetch as the previous prefetch. The initiation of prefetch operations is triggered by detection of a sequential read stream in a plurality of read requests from the host computer. When the prefetch size is increased, the preset amount of the increase equals the number of records in the read request from the host computer. After requested records are returned from the cache to the host computer in response to the read request, storage space in the cache used by the returned requested records is released.