A system and method for storage and retrieval of pervasive and mobile content is provided. System may be comprised of a controller and a plurality of storage devices. Plurality of storage devices may include a first storage device located in a first geographic location and a second storage device located in a second geographic location. The controller may be operably connected to each storage device. The controller may also be capable of locating a first storage device containing data and transferring the data between the first storage device and a second storage device. The second storage device may be capable of transferring data to a host, which may be operably connected to the second storage.

Embodiments of the present disclosure generally relate to a target device handling overlap write commands. In one embodiment, a target device includes a non-volatile memory and a controller coupled to the non-volatile memory. The controller includes a random accumulated buffer, a sequential accumulated buffer, and an overlap accumulated buffer. The controller is configured to receive a new write command, classify the new write command, and write data associated with the new write command to one of the random accumulated buffer, the sequential accumulated buffer, or the overlap accumulated buffer. Once the overlap accumulated buffer becomes available, the controller first flushes to the non-volatile memory the data in the random accumulated buffer and the sequential accumulated buffer that was received prior in sequence to the data in the overlap accumulated buffer. The controller then flushes the available overlap accumulated buffer, ensuring that new write commands override prior write commands.

A method of writing data to persistent storage includes (a) for each data block of a set of data blocks, storing data of that data block at an offset within a log segment of the persistent storage in conjunction with a logical block address (LBA) of that data block on the persistent storage, a size of the log segment being larger than a size of each data block, (b) identifying a particular log segment of the persistent storage that has become filled with data blocks, and (c) upon identifying the particular log segment as having become filled, inserting pointers to respective data blocks stored within the particular log segment into respective locations defined by the respective LBA of each respective data block within a map tree.

A system is provided. The system includes a storage controller configured to receive a prefetch command from a host interface. The storage controller includes a read cache memory that stores prefetch data in response to the prefetch command and a plurality of storage tiers coupled to the storage controller and providing the prefetch data. The plurality of storage tiers includes a fastest storage tier that stores the prefetch data if the read cache memory discards the prefetch data after storing the prefetch data.

Systems and processes are disclosed to preserve data integrity during a storage controller failure. In some examples, a storage controller of an active-active controller configuration can back-up data and corresponding cache elements to allow a surviving controller to construct a correct state of a failed controller's write cache. To accomplish this, the systems and processes can implement a relative time stamp for the cache elements that allow the backed-up data to be merged on a block-by-block basis.

Provided are a computer program product, system, and method for using mirror indicators to determine whether to mirror tracks in a data set in a primary volume mirrored to a secondary volume. A table is read. The table is maintained by a primary controller managing the primary volume that includes a mirror indicator for each of a plurality of tracks in at least one data set configured in the primary volume indicating whether a track is to be mirrored to the secondary volume. Record sets are read from a cache of the primary controller for the tracks in primary volume having the mirror indicators in the table indicating that the track is to be mirrored. The write data in the read record sets is applied to tracks in the secondary volume mirroring the tracks in the primary volume.

Provided are a computer program product, system, and method for using mirror indicators to indicate whether to mirror tracks in a data set in a primary volume mirrored to a secondary volume. A table includes a mirror indicator for each of a plurality of tracks in at least one data set in the primary volume indicating whether a track is to be mirrored to the secondary volume. In response to a write command of write data for one of the tracks in the primary volume, creating a record set in a cache for the primary volume including write data for the track to transfer to the secondary volume in response to the mirror indicator for the track indicating that the track is to be mirrored. The write data in the record set is transferred from the cache to the secondary volume.

According to one embodiment, a memory system is connectable to a host including a first memory. The memory system includes a non-volatile second memory, a volatile third memory, and a controller. The controller uses the third memory as a work memory, and executes data transfer between the host and the second memory. The controller receives a first command to change a power mode from the host. The controller transfers first data to the first memory and transfers second data to the second memory in response to the receipt of the first command. The controller transmits a response of completion of data transfer. The first data and the second data are included in third data. The third data is data in the third memory.

A technique for controlling acceptance of host application data into a data log in a data storage system includes selectively accepting or refusing newly arriving host data into the data log based on a comparison between an oldest entry in the data log and an age threshold. The age threshold is dynamically updated based on system heuristics. As long as the oldest log entry is younger than the age threshold, the data log continues to accept newly arriving host application data, acknowledging IO requests to host applications as the data specified in those requests is entered into the log. However, when the oldest log entry is older than the age threshold, new log entries are temporarily refused entry into the data log. Instead, newly arriving data are placed in a pending list, where they are kept until the data log is again accepting new log entries.

In an example, an apparatus may include a memory comprising a number of groups of memory cells and a controller coupled to the memory and configured to track respective invalidation velocities of the number of groups of memory cells and to assign categories to the number of groups of memory cells based on the invalidation velocities.