A technique for managing cache in a storage system that supports data deduplication renders each of a set of data blocks as multiple sub-blocks and loads a cache-resident digest database on a per-block basis, selectively creating new digest entries in the database for all sub-blocks in a block, but only for blocks that contain no duplicate sub-blocks. Sub-blocks of blocks containing duplicates are excluded. By limiting digest entries to sub-blocks of blocks that contain no duplicates, the storage system limits the size of the digest database, and thus of the cache, while also biasing the contents of the digest database toward entries that are likely to produce deduplication matches in the future.

A method for controlling operations of an asynchronous FIFO memory includes: determining a current depth of the asynchronous FIFO memory according to at least one of a clock ratio, a burst length and a continuous transmission length, where the clock ratio is a ratio of a frequency of a first clock signal used by a master device to a frequency of a second clock signal used by a slave device; configuring one or more entries of the asynchronous FIFO memory to be used according to the current depth; and controlling a plurality of FIFO clock signals provided to the asynchronous FIFO memory according to the current depth. One FIFO clock signal corresponds to one entry, and one or more FIFO clock signals corresponding to one or more entries that are not configured according to the current depth are disabled.

A computational device determines whether one or more tasks are waiting for accessing a cache for more than a predetermined amount of time while least recently used (LRU) based replacement of tracks are being performed for the cache via demotion of tracks from a LRU list of tracks corresponding to the cache. In response to determining that one or more tasks are waiting for accessing the cache for more than the predetermined amount of time, in addition to continuing to demote tracks from the LRU list, a plurality of deadlock prevention demotion tasks demote tracks from the cache.

A computational device determines whether one or more tasks are waiting for accessing a cache for more than a predetermined amount of time while least recently used (LRU) based replacement of tracks are being performed for the cache via demotion of tracks from a LRU list of tracks corresponding to the cache. In response to determining that one or more tasks are waiting for accessing the cache for more than the predetermined amount of time, in addition to continuing to demote tracks from the LRU list, a deadlock prevention application demotes tracks from at least one region of a cache directory that identifies all tracks in the cache.

A storage controlling apparatus includes a processor, wherein the processor: controls a first counter configured to count, among data stored in a cache memory and relating to an access request, a number of data which are not written in storage volumes of a target of the access request, for each storage volume; determines, in response to reception of a first access request, whether or not a first ratio of a counter value of the first counter to a number of data allocated already to the cache memory into a first storage volume exceeds a first threshold value, the counter value of the first counter corresponding to the first storage volume which is a target of the first access request; and performs a write back process of data from the cache memory into the first storage volume where the first ratio exceeds the first threshold value.

The exemplary embodiments provide an in-memory database which uses a non-volatile memory as a primary storage, uses a volatile memory for data which exceeds a predetermined capacity of the non-volatile memory, as a secondary storage, and periodically stores a log file for data stored in the volatile memory in a block device, thereby ensuring a data consistency while overcoming a capacity limit of the non-volatile memory.

A semiconductor apparatus that selects a first packet from a plurality of packets stored in a buffer and transfers the first packet. The semiconductor apparatus switches a plurality of different conditions for grouping the plurality of packets according to a priority order of the plurality of conditions; and selects the first packet from a plurality of packets pertaining to a group extracted on a condition selected by the switching according to a given selecting scheme, and transfers the first packet from the buffer.

With regard to a function group including all or some functions included in one of multiple binary codes stored in the memory device, a binary code including a first function that is executed at a first timepoint is loaded into a first memory area at a second timepoint that precedes the first time point, thereby minimizing the operation delay time of the memory system, and minimizing the overhead occurring in the processing of calling a specific function.

A method of adjusting temporal and spatial granularities associated with operation of a virtualized file system, the method including analyzing past workloads of a plurality of virtual machines associated with the virtualized file system, and adjusting the temporal and spatial granularities to be similar to average re-access temporal and spatial distances of data sets corresponding to the past workloads.

According to some example embodiments, a method includes: receiving, by a processor, from a data source, a processing profile comprising input data blocks and a plurality of operations for executing using the input data blocks; executing, by the processor, one or more of the operations of the processing profile to generate a new output data after each of the executed one or more operations; storing, by the processor, the new output data from at least one of the one or more operations as intermediate cache data; and transmitting, by the processor, the new output data from a final operation from among the one or more operations to the data source for display thereby.