Emc IP Holding Company LLC

Emc Corporation

Timothy Johnson

Steven T McClure

Stephen Richard Ives

Peng Yin

Zhi-Gang Liu

Jiahui Wang

Robert DeCrescenzo

Michael Garvey

Scott B Gordon

Christopher Monti

Akash Agrawal

A method of distributed management of recovery of multi-controller NVMe drives includes detecting a path failure of a PCIe path from a first storage node to a first controller on the multi-controller NVMe drive, and initially attempting to correct the path failure using a controller level reset. If the controller level reset is unsuccessful, an alternative path to the controller is sought, and if that is unsuccessful a drive level reset operation is coordinated by all storage nodes with controllers executing on the NVMe drive. To coordinate reset of the NVMe drive, one storage node is elected master. Each node (both slave and master) initiates quiescing of IO operations on its respective controller, and after quiescing has completed, initiates shutdown of its respective controller. Once all controllers are shut down, the master initiates reset of the NVMe drive. Timeouts are used to constrain completion of the quiescing and shutdown operations.

System and method for managing recovery of multi-controller NVMe drives

A method for safeguarding data stored in a memory of a data storage system includes monitoring values of a subset of environmental variables associated with the data-storage system and updating a portion of a table containing values of environmental variables associated with the data-storage system. The table includes values for environmental variables that are not in the subset of environmental variables monitored. The values of the environmental variables are then inspected. On the basis of the inspection, a condition in which there exists a high-risk of data loss is determined.

Determining environmental availability in a storage subsystem

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Leicester, MA, United States of America

Timothy Johnson