Western Digital Technologies, Inc.

Ravishankar Surianarayanan

Matias Bjorling

Arvind Kumar V M

A data storage device includes a memory device and a controller coupled to the memory device. The memory device is arranged into at least a first super device and a second super device, each of the super devices having a plurality of active zones. The controller is configured to determine that each of the super devices includes both cold zones and hot zones, where a cold zone is a zone that is overwritten less than a hot zone. The controller is further configured to move cold zones from one super device to another super device upon determining that the another super device is below a threshold limit, where the threshold limit is a minimum free space to be maintained in a super device. The controller is further configured to move cold zones between super devices, such that the cold zones are concentrated in at least one super device.

Purposeful super device imbalance for ZNS SSD efficiency

A data storage device includes a memory device and a controller coupled to the memory device. The memory device includes at least a first super device and a second super device. Each of the super devices includes a plurality of active zones and a threshold value for a number of cold zones. The controller classifies zones as either a cold zone or hot zone depending the number of resets to the zone. If the number of resets to the zone is greater than a threshold reset value, then the zone is classified as a hot zone, otherwise the zone is classified as a cold zone. The controller is configured to determine that the number of cold zones is greater than the threshold value for a super device and move data from at least one cold zone from the super device to a zone of another super device.

Solution for super device imbalance in ZNS SSD

Multiple logical-to-physical translation tables (L2PTTs) for data storage devices having indirection units of different sizes. In one embodiment, a data storage controller includes a memory interface configured to interface with a memory, the memory including a zoned namespace, the zoned namespace including a plurality of zones. The data storage controller includes a controller memory including two or more logical-to-physical translation tables (L2PTTs), and an electronic processor. The electronic processor is configured to receive data to be stored in a zone of the plurality of zones, determine whether the zone is an active zone, select, in response to determining that the zone is the active zone, a first L2PTT having a first indirection unit size, and select, in response to determining that the zone is not the active zone, a second L2PTT having a second indirection unit size.

Multiple indirection sizes for logical-to-physical translation tables

A data storage device includes a memory device and a controller coupled to the memory device. The controller is configured to allocate two or more zones to a first superblock of a plurality of superblocks. The controller is further configured to allocate a zone to a second superblock, where the second superblock only stores data of the zone. The first superblock has a first priority and the second superblock has a second priority, where the second priority is greater than the first priority. Data is moved from the first superblock to another superblock dedicated for a single zone after the first superblock is closed.

Support higher number of active zones in ZNS SSD

Systems and methods described herein provide for determining priority levels within one or more data streams established between a host computing device and a storage device. Data streams that have been assigned a sufficiently high priority may be provided additional processing resources available within the storage device. These additional processing resources may include an increased number of write buffers, superblocks, and access to other ancillary resources that facilitate an increased level of performance compared to data streams not provided additional processing resources. The assignment of priority to the data streams can occur through the use of one or more priority identifiers. Many types and scales of priority identifiers may be used. The establishing of this system of priority identifiers can occur by the storage device notifying the hose of the accepted priority identifier usage. In other embodiments, the storage device may come preconfigured with a priority indication system and scale.

Providing priority indicators for NVMe data communication streams

A data storage device includes a memory device and a controller coupled to the memory device. The memory device includes a plurality of super devices. The controller is configured to set a free space threshold value for amount of free space that each super device of the plurality of super devices can have, determine that at least one super device of the plurality of super devices is at or above the free space threshold, determine that cold zones are disposed in more than one super device of the plurality of super devices, move data from the cold zones to a first super device of the plurality of super devices wherein after moving the data, all super devices are below the free space threshold, and allocate all new super blocks among the plurality of super devices without allocating any new super blocks to the first super device.

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Bengaluru, India

Ravishankar Surianarayanan