Sandisk Technologies Inc.

Michael Ionin

Yehuda Hahn

Alexander Bazarsky

Karin Inbar

Instead of ignoring workflow or priority of tenant, modify the write path according to the tenant behavior and system priority using the multi-tenant storage device. When writing information, the write path usually includes RAM memory where the host or device copies the data. The data is copied to the NVM storage element. The RAM memory may be either part of the storage controller (either SRAM or DRAM) or part of the host (like DRAM in HMB) that may be controlled by the storage controller. The RAM memories are used for different goals by the storage controller and optimizing the overall system performance (write/read) is a priority of the storage device. In multi-tenant architectures, the different tenants may have different priorities to have their requirements fulfilled. The tenant priority is passed by the host to the storage device through an interface and either be static or change dynamically during the device operation. Optimizing the write paths according to tenant workload and priority may be done by a module in the storage controller.

Optimizing usage of multiple write paths on multi-tenant storage devices

A controller memory buffer (CMB) is a portion of volatile memory of a controller of a data storage device that is allocated to a host device for use by the host device. When the CMB is not fully utilized, the controller may determine that at least a portion of the unutilized space of the CMB may be used for non-host data. The at least a portion is based on a number of past workloads and a current workload of the CMB. An amount of available space of the CMB that the controller may utilize is dependent on the number of past workloads and the current workload of the CMB. Thus, the volatile memory of the controller may be more optimally utilized.

Excess CMB utilization by storage controller

During data storage device operation, data of multiple blocks of a non-volatile memory device, logically grouped as a jumboblock, may be protected by an exclusive or (XOR) signature, where the XOR signature may be used to recover data of a block of the multiple blocks. During a recovery/relocation operation, data of the jumboblock is read from the non-volatile memory device during the recovery of the lost data and again when the data is relocated. However, because the data read during data storage device operation is temporarily stored in a volatile memory device, the controller utilizes the relevant data stored in the volatile memory device and the data stored in the non-volatile memory device to recover corrupted data. Thus, the amount of reads from the non-volatile memory device decreases due to the relevant data is read from the volatile memory device, which may improve data storage device performance.

Pre-emptive operations for faster XOR recovery and relocation

In order to guarantee data validity of data read from a memory device of the data storage device to a host device, a controller of the data storage device may calculate a cyclic redundancy code (CRC) signature of the decoded data and compare the CRC signature of the decoded data with a CRC signature of the data. The CRC signature of the data is generated during a write operation of the data to the memory device. Rather than returning an uncorrectable error correction code error (UECC) error to the host device when the CRC signature of the decoded data does not match the CRC signature of the data, the controller executes the read command again. By using a different buffer to store the decoded data, the controller may confirm whether the error stemmed from the read path or the error was not from the read path.

Enhanced end to end system failure recovery

A data storage device includes a memory device and a controller coupled to the memory device. When data received by the controller, from a host device or from a non-volatile memory of the data storage device, the controller maintains table tracking the location of the data. The table may include a current location of the data in a volatile memory of the controller or the data storage device as well as the current location of the data a latch of the non-volatile memory. The table may further associate the location with a logical block address, such that when the host device requests the data not yet programmed to the non-volatile memory or data that is part of a data relocation operation, the controller may utilize the table to locate the relevant data and provide the data to the host device.

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Rehovot, Israel

Michael Ionin