Provided are a computer program product, system, and method for considering a frequency of access to groups of tracks and density of the groups to select groups of tracks to destage. One of a plurality of densities for one of a plurality of groups of tracks is incremented in response to determining at least one of that the group is not ready to destage and that one of the tracks in the group in the cache transitions to being ready to destage. A determination is made of a group frequency indicating a frequency at which tracks in the group are modified. At least one of the density and the group frequency is used for each of the groups to determine whether to destage the group. The tracks in the group in the cache are destaged to the storage in response to determining to destage the group.

Provided are a computer program product, system, and method for considering a density of tracks to destage in groups of tracks to select groups of tracks to destage. Groups of tracks in the cache are scanned to determine whether they are ready to destage. A determination is made as to whether the tracks in one of the groups are ready to destage in response to scanning the tracks in the group. A density for the group is increased in response to determining that the group is not ready to destage. The group is destaged in response to determining that the density of the group exceeds a density threshold.

In one embodiment, a system includes a disk cache and a controller configured to create a cache resident partition in the disk cache, the cache resident partition being configured to store data thereto that is not subject to HSM, manage the cache resident partition to have a size that is greater than a first minimum size and less than or equal to a total size of the disk cache, receive data to store to the disk cache, store the data to the cache resident partition at least initially, create tape-managed partitions in the disk cache, each of the tape-managed partitions being configured to store data that is subject to HSM, and manage the tape-managed partitions to have a size that is greater than a second minimum size and less than or equal to a total size of the disk cache less a size of all other partitions combined.

In a memory device, odd bit lines of a flag memory cell array are connected with a short circuit to a dynamic data cache. Even bit lines of the flag memory cell array are disconnected from the dynamic data cache. When an even page of a main memory cell array is read, the odd flag memory cells, comprising flag data, are read at the same time so that it can be determined whether the odd page of the main memory cell array has been programmed. If the flag data indicates that the odd page has not been programmed, threshold voltage windows can be adjusted to determine the states of the sensed even memory cell page.

Performing failover processing between a production host and a backup host, a storage system is connected to the production host and the backup host. In response to a failure of the production host, metadata is obtained of data blocks that have been cached from an elastic space located in a fast disk of the storage system. A storage capacity of the elastic space is expanded. Data blocks are obtained to which the metadata corresponds according to the metadata and the storage capacity of the expanded elastic space, and storing the same in the expanded elastic space. In response the backup host requesting the data blocks to which the metadata corresponds, and the data blocks to which the metadata corresponds have already been stored in the expanded elastic space, data blocks are obtained to which the metadata corresponds from the expanded elastic space and transmitting the same to the backup host.

A data storage system incorporating a write-caching subsystem that implements a steady-state media-based cache is described. The steady-state of the media-based cache can be obtained by directing non-sequential write commands and data received from the host device to multiple independent cache locations and, thereafter, selectively copying or moving such data between the caches so that none of the caches are either too full or too empty. In this manner, a non-sequential write command can be cached in a power-safe manner until it is efficient and/or convenient to write such data to the mainstore portion of the physical media.

Implementations disclosed herein provide a method comprising determining a workload on a disk cache with a storage device controller, determining a state of a free pool of the disk cache, receiving a data write request to the disk cache, segregating the free pool of the disk cache into a plurality of allocation units, allocating the plurality of allocation units out of order, as compared to a physical arrangement order of the allocation units in the disk cache, based on the workload, and storing data in the plurality of allocation units.

A method of storing data is provided. The method includes receiving commands from a system memory controller of a computer system. The commands include logical addresses and are received by a computer memory device comprising a parallel memory interface operatively coupled to the system memory controller and operatively coupled to a non-volatile memory. The method further includes responding to the commands by translating the received logical addresses to corresponding physical addresses of the non-volatile memory, receiving data from the system memory controller by the parallel memory interface, and storing the data at memory locations of the non-volatile memory corresponding to the physical addresses.

Embodiments described herein provide systems and methods for streaming data to multiple reading clients. More particularly, embodiments described herein provide systems and methods for using a memory buffer to stream file data from a mounted tape file system volume to multiple reading clients.

Systems and methods of building massively parallel computing systems using low power computing complexes in accordance with embodiments of the invention are disclosed. A massively parallel computing system in accordance with one embodiment of the invention includes at least one Solid State Blade configured to communicate via a high performance network fabric. In addition, each Solid State Blade includes a processor configured to communicate with a plurality of low power computing complexes interconnected by a router, and each low power computing complex includes at least one general processing core, an accelerator, an I/O interface, and cache memory and is configured to communicate with non-volatile solid state memory.