Abstract: A data storage system with a cache organizes cache windows into lists based on the number of cache lines accessed during input/output operations. The lists are maintained in temporal queues with cache windows transferred from prior temporal queues to a current temporal queue. Cache windows are removed from the oldest temporal queue and least accessed cache window list whenever cached data needs to be removed for new hot data.

Abstract: A cache device for the caching of data and specifically for the identification of stale data or a thrashing event within the cache device is described. Further a cache device for the prioritization of cached data in the cache device during a thrashing event as well as stale cached data in the cache device are described. Methods associated with the use of the caching device for the caching of data and for the identification of data in a thrashing event or the identification of stale cached data are also described.

Abstract: A data storage system with a cache organizes cache windows into lists based on the number of cache lines accessed during input/output operations. The lists are maintained in temporal queues with cache windows transferred from prior temporal queues to a current temporal queue. Cache windows are removed from the oldest temporal queue and least accessed cache window list whenever cached data needs to be removed for new hot data.

Abstract: Data is distributed to solid-state disks (SSDs) using the RAID-0 technique. Based on a utilization of a first region of a first one of the SSDs, the first region is selected for garbage collection. Valid data from the first region is copied to an active region of the first one of the SSDs as part of a process of garbage collection. While the process of garbage collection is being performed, data is distributed to a subset of the SSDs using the RAID-0 technique where the subset of the SSDs does not include the first one of the plurality of nonvolatile solid-state memories selected for garbage collection.

Abstract: Data is distributed to solid-state disks (SSDs) using the RAID-0 technique. Based on a utilization of a first region of a first one of the SSDs, the first region is selected for garbage collection. Valid data from the first region is copied to an active region of the first one of the SSDs as part of a process of garbage collection. While the process of garbage collection is being performed, data is distributed to a subset of the SSDs using the RAID-0 technique where the subset of the SSDs does not include the first one of the plurality of nonvolatile solid-state memories selected for garbage collection.

Abstract: A cache controller having a cache store and associated with a storage system maintains information stored in the cache store across a reboot of the cache controller. The cache controller communicates with a host computer system and a data storage system. The cache controller partitions the cache memory to include a metadata portion and log portion. A separate portion is used for cached data elements. The cache controller maintains a copy of the metadata in a separate memory accessible to the host computer system. Data is written to the cache store when the metadata log reaches its capacity. Upon a reboot, metadata is copied back to the host computer system and the metadata log is traversed to copy additional changes in the cache that have not been saved to the data storage system.

Abstract: A method of managing a plurality of least recently used (LRU) queues having entries that correspond to cached data includes ordering a first plurality of entries in a first queue according to a first recency of use of cached data. The first queue corresponds to a first priority. A second plurality of entries in a second queue are ordered according to a second recency of use of cached data. The second queue corresponds to a second priority. A first entry is selected in the first queue based on the order of the first plurality of entries in the first queue. A recency property associated with the first entry is compared with a recency property associated with a second entry in the second queue. Based on a result of this comparison, the first entry and the second entry may be swapped.

Abstract: A data storage system includes two tiers of caching memory. Cached data is organized into cache windows, and the cache windows are organized into a plurality of priority queues. Cache windows are moved between priority queues on the basis of a threshold data access frequency; only when both a cache window is flagged for promotion and a cache window is flagged for demotion will a swap occur.

Abstract: A cache device for the caching of data and specifically for the identification of stale data or a thrashing event within the cache device is described. Further a cache device for the prioritization of cached data in the cache device during a thrashing event as well as stale cached data in the cache device are described. Methods associated with the use of the caching device for the caching of data and for the identification of data in a thrashing event or the identification of stale cached data are also described.