Western Digital Technologies, Inc.

Sandisk Technologies Inc.

Einav Zilberstein

Hadas Oshinsky

Rotem Sela

Amir Shaharabany

Karin Inbar

Yehuda Hahn

Tal Heller

Maayan Suliman

Alon Marcu

Stella Achtenberg

Eyal Sobol

Asher Druck

Yigal Eli

Omer Gilad

Liat Hod

Tal Shaked

Alex Lemberg

Yuliy Izrailov

Enosh Levi

Adir Moshen HaCohen

Oren Ben Hayun

Matar Krizhak

Nadav Sober

Omer Katz

Zoned memory typically requires write commands to be sent from a host to a data storage device in logical block address (LBA) sequential order. Instead of rejecting out-of-order write commands, the data storage device can execute those commands and internally deal with the out-of-order problem. For example, the data storage device can use a special zone logical-to-physical address table, use a temporary zone data buffer, and/or store a data's LBA in a header for later matching.

Data storage device and method for handling write commands in zoned storage

A data storage device includes a memory device and a controller coupled to the memory device. The controller is configured to add one or more entries to a log file system (LFS) invalidation table and scan the LFS invalidation table during a storage optimization operation. Each entry of the one or more entries maps a new valid logical block address (LBA) to an old invalidated LBA. The new valid LBA is updated version of the old invalidated LBA. The storage optimization operation includes moving data from a first location to a second location.

Log file system (LFS) invalidation command and operational mode

A storage system is provided that performs a defragmentation operation or proactive garbage collection in its memory based on a command from a host. The command specifies which blocks in the memory should take part in the defragmentation operation by specifying a maximum amount of valid data that a block can have to qualify for defragmentation. That way, the storage system only performs defragmentation on those blocks that meet the validity criteria provided by the host. This can help improve performance of the storage system while reducing the degree of negative tradeoffs that may come with defragmentation or proactive garbage collection.

Storage system and method for optimizing host-activated defragmentation and proactive garbage collection processes

A stream set classification process may be implemented to classify streams opened by a host device on a data storage device. The data storage device may internally classify the streams into different stream classifications using a set of performance metrics. Stream classifications that cause the data storage device to show the greatest gains when compared with a set of baseline performance metrics for the data storage device and/or when compared with other stream classifications, may be selected by the data storage device and/or the host device for subsequent write operations.

Adaptive multi-stream classification for data storage systems

A storage system allocates single-level cell (SLC) blocks in its memory to act as a write buffer. A host sends the storage system a threshold indicating an amount of data that should be stored in the write buffer before the storage system flushes the write buffer to multi-level cell (MLC) blocks in the memory. Using this threshold can extend the amount of time that data is maintained in the write buffer, which can reduce the write-amplification factor and power consumption, as well as increase read performance of the data.

Storage system and method for delaying flushing of a write buffer based on a host-provided threshold

A storage system uses blocks of memory that are sized larger than a size of a zone. This means that the storage system stores multiple zones in a given block. Storing zones with different zone properties in a given block can be problematic, so the storage system obtains zone property information for each zone and stores zones with similar zone properties in a given block.

Storage system and method for data placement in zoned storage

A storage system analyzes a logical block address range of data in a resolution of a defragmentation unit. The storage system determines whether a given defragmentation unit is fragmented above a threshold and performs a defragmentation operation accordingly. Additionally or alternatively, the storage system can receive a suggested logical block address read order from a host to improve performance.

Storage system and method for optimizing write-amplification factor, endurance, and latency during a defragmentation operation

A storage system determines a memory fragmentation level for each of a plurality of logical block address ranges. The memory fragmentation level for a given logical block address range is determined according to the number of memory senses required to read that logical block address range in its current state of fragmentation and the number of memory senses required to read that logical block address range assuming no fragmentation. The memory fragmentation level correlates to the sequential read performance for that logical block address range in that an increase in the memory fragmentation level results in a decrease in sequential read performance.

Storage system and method for quantifying storage fragmentation and predicting performance drop

A storage system allocates single-level cell (SLC) blocks in its memory to act as a write buffer and/or a read buffer. When the storage system uses the SLC blocks as a read buffer, the storage system reads data from multi-level cell (MLC) blocks in the memory and stores the data in the read buffer prior to receiving a read command from a host for the data. When the storage system uses the SLC blocks as a write buffer, the storage system retains certain data in the write buffer while other data is flushed from the write buffer to MLC blocks in the memory.

Storage system and method for using read and write buffers in a memory

A storage system determines whether its memory is fragmented (e.g., based on a host read pattern that indicates that a sequential file is being read, but the number of data sense operations required to perform this read indicates that file is stored non-sequentially in the memory). If the storage system determines that its memory is fragmented, the storage system can perform a defragmentation operation on the memory. This defragmentation operation can be done invisibly to the host (i.e., without receiving any hint or instruction from the host to perform the defragmentation operation).

Storage system and method for automatic defragmentation of memory

A method and system for visualizing a correlation between host commands and storage system performance are provided. In one embodiment, a method comprises receiving information concerning host operations of a host performed over a time period; receiving information concerning storage system operations of a storage system performed over the time period; and simultaneously displaying both the host operations and the storage system operations over the time period. Other embodiments are possible, and each of the embodiments can be used alone or together in combination.

Method and system for visualizing a correlation between host commands and storage system performance

A storage system and method are provided for flush optimization. In one embodiment, a storage system is provided comprising a cache, a non-volatile memory, and a controller. The controller is configured to: store, in the cache, data received from a host and to be written in the non-volatile memory; receive a command from the host to move the data stored in the cache into the non-volatile memory; without having executed the command, send a confirmation to the host that the command was executed; and execute the command after sending the continuation to the host.

Storage system and method for flush optimization

A storage module and method for regulating garbage collection operations based on write activity of a host are disclosed. In one embodiment, a storage module determines whether the host is operating in a burst mode by determining whether write activity of the host over a time period exceeds a threshold. The write activity can comprise one or both of (i) an amount of data received from the host to be written in the storage module and (ii) a number of write commands received from the host. If the host is operating in the burst mode, the storage module limits an amount of garbage collection operations during the burst mode. When the host is no longer operating in the burst mode, the storage module increases an amount of garbage collection operations.

Storage module and method for regulating garbage collection operations based on write activity of a host

A storage module and method for adaptive burst mode are provided. In one embodiment, a storage module is provided comprising a memory and a controller. The controller is configured to receive a plurality of write commands from a host controller in communication with the storage module, store the plurality of write commands in a command queue in the storage module, and choose one of a plurality of burst modes in which to operate the memory based on how many write commands are stored in the command queue.

Growing community of inventors

Had Hasharon, Israel

Einav Zilberstein