Fractional redundant array of silicon independent elements
AssigneeSeagate Technology LLC
InventorEarl T. Cohen
Life of this patent
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Abstract
Higher-level redundancy information computation enables a Solid-State Disk (SSD) controller to provide higher-level redundancy capabilities to maintain reliable operation in a context of failures of non-volatile (e.g. flash) memory elements during operation of an SSD implemented in part by the controller. For example, a first computation is an XOR, and a second computation is a weighted-sum. Various amounts of storage are dedicated to storing the higher-level redundancy information, such as amounts equivalent to an integer multiple of flash die (e.g. one, two, or three entire flash die), and such as amounts equivalent to a fraction of a single flash die (e.g. one-half or one-fourth of a single flash die).
Claims20
A method comprising:
- operating a data storage device in a first redundancy mode, the first redundancy mode including reserving a first number of data storage locations, from a stripe of data storage locations, for storing redundancy data for the stripe, the stripe configured to include a data storage location from a plurality of different physical storage devices;
- determining a failure of a specific data storage location from the stripe;
- and
- based on the failure, dynamically transitioning from the first redundancy mode to a second redundancy mode, including adjusting a number of data storage locations available for redundancy data in the stripe from the first number to a second number of data storage locations from the stripe.
An apparatus comprising:
- a storage device controller circuit configured to:
- operate a data storage device in a first redundancy mode, the first redundancy mode including reserving a first number of data storage locations, from a stripe of data storage locations, for storing redundancy data for the stripe, the stripe configured to include data storage locations from different physical storage devices;
- determine a failure of a specific data storage location from the stripe;
- and
- based on the failure, dynamically transition from the first redundancy mode to a second redundancy mode, including reserving a second number of data storage locations, different from the first number, from the stripe for storing redundancy data for the stripe.
A memory device storing instructions that, when executed, cause a processor to perform a method comprising:
- operating a data storage drive in a first redundancy mode, the first redundancy mode including reserving a first number of data storage locations, from a stripe of data storage locations, for storing redundancy data for the stripe, the stripe configured to include a data storage location from a plurality of different physical storage devices;
- determining a failure of a specific data storage location from the stripe;
- and
- based on the failure, dynamically transitioning from the first redundancy mode to a second redundancy mode having a different number of data storage locations reserved for storing redundancy data, including reserving a second number of data storage locations for storing redundancy data for the stripe.
Dependencies are inferred from the claim text.