Abstract: A method includes accessing a cache including a first cache block and setting the first cache block to a passive sub-state, where the first cache block in the passive sub-state is configured to be accessed or modified. The method also includes receiving at least one access or modification request of the first cache block and transitioning the first cache block from the passive sub-state to an active sub-state. The method also includes incrementing an ordinal cache activation count at an active cache counter in response to the transitioning, where the active cache counter is configured to track the activation counts such that oldest cache use counts are designated to be overwritten in the cache in an oldest-first fashion.

Abstract: A method of adjusting asynchronous cache operations on a cache device includes accessing the cache device each cache window having a plurality of cache blocks, and each cache block having corresponding metadata indicating a status of the cache block. The method also includes receiving, at a first cache block, a first input/output operation and updating a first metadata of the first cache block, the first metadata being marked as dirty. The method also includes receiving, at a second cache block, a second input/output operation and updating a second metadata of the second cache block, the second metadata being marked as dirty. The method also includes grouping, in a page, the first and second input/output operations and updating, in a single operation according to the page, the first and second cache blocks according to the first and second input/output operations. The first and second metadata are then marked as non-dirty.

Abstract: A method of adjusting asynchronous cache operations on a cache device includes accessing the cache device each cache window having a plurality of cache blocks, and each cache block having corresponding metadata indicating a status of the cache block. The method also includes receiving, at a first cache block, a first input/output operation and updating a first metadata of the first cache block, the first metadata being marked as dirty. The method also includes receiving, at a second cache block, a second input/output operation and updating a second metadata of the second cache block, the second metadata being marked as dirty. The method also includes grouping, in a page, the first and second input/output operations and updating, in a single operation according to the page, the first and second cache blocks according to the first and second input/output operations. The first and second metadata are then marked as non-dirty.

Abstract: A method includes accessing a cache including a first cache block and setting the first cache block to a passive sub-state, where the first cache block in the passive sub-state is configured to be accessed or modified. The method also includes receiving at least one access or modification request of the first cache block and transitioning the first cache block from the passive sub-state to an active sub-state. The method also includes incrementing an ordinal cache activation count at an active cache counter in response to the transitioning, where the active cache counter is configured to track the activation counts such that oldest cache use counts are designated to be overwritten in the cache in an oldest-first fashion.

Abstract: Methods, systems, and computer-readable storage media for performing scattered atomic I/O writes in a storage device. A list of block I/O write requests to be completed as an atomic unit is received from a requester with at least two of the block I/O write requests specifying non-contiguous data locations on a storage media. The plurality of block I/O write requests are buffered in a write buffer with each buffer entry marked as having an invalid state, wherein marking a buffer entry as having an invalid state prevents it from being flushed to the storage media. Upon buffering all of the plurality of block I/O writes, all of the buffer entries are marked as having a valid state at the same time. Upon marking all of the buffer entries as having a valid state, successful completion of the list of block I/O write requests is acknowledged to the requester.

Abstract: Methods, systems, and computer-readable storage media for performing scattered atomic I/O writes in a storage device. A list of block I/O write requests to be completed as an atomic unit is received from a requester with at least two of the block I/O write requests specifying non-contiguous data locations on a storage media. The plurality of block I/O write requests are buffered in a write buffer with each buffer entry marked as having an invalid state, wherein marking a buffer entry as having an invalid state prevents it from being flushed to the storage media. Upon buffering all of the plurality of block I/O writes, all of the buffer entries are marked as having a valid state at the same time. Upon marking all of the buffer entries as having a valid state, successful completion of the list of block I/O write requests is acknowledged to the requester.

Abstract: Embodiments of the present invention are directed to a logical disk provided by a storage system. The logical disk comprises a number of data segments mapped to physical data-storage, metadata, stored in an electronic memory and/or mass-storage devices, that includes, for each segment of the logical disk, a three-bit field, and a set of operations, carried out by a storage-system controller, that can be directed to the logical disk by an entity that accesses the storage system, including a snapclone operation that generates a snapclone of the logical disk and a snapshot operation that generates a snapshot of the logical disk, an existing snapshot of the logical disk, or a snapclone of the logical disk.

Abstract: A method is described where data is copied from a plurality of first discrete physical storage means to a plurality of second discrete physical storage means, where the data is split across the plurality of first discrete physical storage means, the method comprising the steps of copying blocks of the split data in parallel between a plurality of pairs of said first and second discrete physical storage means, wherein the copying is performed in such a way that there is no more than one copy process occurring in respect of any single pair of first and second physical storage unit at any one time. The data may be split into blocks where each consecutive block is stored on a separate discrete physical storage means.