An SCM memory mode NVDIMM-N cache system includes an SCM subsystem, and an NVDIMM-N subsystem having at volatile memory device(s) and non-volatile memory device(s). A memory controller writes data to the volatile memory device(s) and, in response, updates a cache tracking database. The memory controller then writes a subset of the data to the SCM subsystem subsequent to the writing of that data to the volatile memory device(s) and, in response, updates the cache tracking database. The memory controller then receives a shutdown signal and, in response, copies the cache tracking database to the volatile memory device(s) in the NVDIMM-N subsystem. The NVDIMM-N subsystem then copies at least some of the data and the cache tracking database from the volatile memory device(s) to the non-volatile memory device(s) prior to shutdown. The data and the cache tracking database may then be retrieved from non-volatile memory device(s) when the system is restored.

The devices within an inter-device processing system maintain data coherency in the last level caches of the system as a cache line of data is shared between the devices by utilizing a directory in one of the devices that tracks the coherency protocol states of the memory addresses in the last level caches of the system.

A system includes a read/write module and a caching module. The read/write module is configured to access a first portion of a recording surface of a rotating storage device. Data is stored on the first portion of the recording surface of the rotating storage device at a first density. The caching module is configured to cache data on a second portion of the recording surface of the rotating storage device at a second density. The second portion of the recording surface of the rotating storage device is separate from the first portion of the recording surface of the rotating storage device. The second density is less than the first density.

A hybrid storage system is described having a mixture of different types of storage devices comprising rotational drives, flash devices, SDRAM, and SRAM. The rotational drives are used as the main storage, providing lowest cost per unit of storage memory. Flash memory is used as a higher-level cache for rotational drives. Methods for managing multiple levels of cache for this storage system is provided having a very fast Level 1 cache which consists of volatile memory (SRAM or SDRAM), and a non-volatile Level 2 cache using an array of flash devices. It describes a method of distributing the data across the rotational drives to make caching more efficient. It also describes efficient techniques for flushing data from L1 cache and L2 cache to the rotational drives, taking advantage of concurrent flash devices operations, concurrent rotational drive operations, and maximizing sequential access types in the rotational drives rather than random accesses which are relatively slower. Methods provided here may be extended for systems that have more than two cache levels.

A memory management method applicable to a data storage device is provided. The memory management method includes steps of: requesting a private memory space from a host; recording a reserved memory space given by the host; dividing a mapping table into a plurality of sub-mapping tables; determining whether a capacity of the reserved memory space is sufficient to store the sub-mapping tables; and if yes, uploading the sub-mapping tables to the reserved memory space via an interface logic.

In various embodiments, methods and systems, for implementing modular data operations, are provided. A data access request, associated with data, is received at a data access component. The data access component selectively implements modular data operations functionality based on configuration settings. A translation table associated with a working set is accessed, based on the configuration settings of the data access component, to determine a location for executing the data access request. The data access request is executed using the cache store or a backing store associated with the working set. The data access request is executed using the location that is determined using the translation table of the working set. The data access request is executed using the cache store when the data is cached in the cache store and the data access requested is executed based on the backing store when the data is un-cached in the cache store.

Aspects of the present disclosure involve a level-two persistent cache. In various aspects, a solid-state drive is employed as a level-two cache to expand the capacity of existing caches. In particular, any data that is scheduled to be evicted or otherwise removed from a level-one cache is stored in the level-two cache with corresponding metadata in a manner that is quickly retrievable.

A file access method and apparatus, and a storage device are presented, where the file access method is applied to a storage device in which a file system is established based on a memory. The storage device obtains, according to a file identifier of a to-be-accessed first target file, an index node of the first target file in metadata, where the index node of the first target file stores information about first virtual space of the first target file in global virtual space. The storage device maps the first virtual space onto second virtual space of a process, and performs addressing on an added file management register to access the first target file according to a start address of the first virtual space and a base address of a page directory of the global file page table stored in the file management register.

According to some embodiments of the present invention, there is provided a hybrid cache memory for a processing device having a host processor, the hybrid cache memory comprising: a high bandwidth memory (HBM) configured to store host data; a non-volatile memory (NVM) physically integrated with the HBM in a same package and configured to store a copy of the host data at the HBM; and a cache controller configured to be in bi-directional communication with the host processor, and to manage data transfer between the HBM and NVM and, in response to a command received from the host processor, to manage data transfer between the hybrid cache memory and the host processor.

A method for demoting data from a cache comprising heterogeneous memory types is disclosed. The method maintains, for a data element in the cache, a write access count that is incremented each time the data element is updated in the cache. The cache includes a higher performance portion and a lower performance portion. The method removes the data element from the higher performance portion in accordance with a cache demotion algorithm. If the data element also resides in the lower performance portion and the write access count is below a first threshold, the method leaves the data element in the lower performance portion. If the data element also resides in the lower performance portion and the write access count is at or above the first threshold, the method removes the data element from the lower performance portion. A corresponding system and computer program product are also disclosed.