Data refresh in flash memory
AssigneeSeagate Technology LLC
InventorsRyan J. Goss, Antoine Khoueir, Ara Patapoutian
Life of this patent
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Abstract
Systems and methods for improving data refresh in flash memory are described. In one embodiment, the method includes identifying a first garbage collection unit (GCU) of the storage system, computing a parity function in relation to the first GCU, identifying a data impairment in a first block, the first block being from the N blocks in the first GCU, removing the first block from the first GCU after identifying the data impairment in the first block, and recomputing the parity function when the first block is not cloned.
Claims20
A storage system comprising:
- a solid state drive comprising multiple flash memory cells divided into multiple blocks, and a storage controller to:
- identify a first garbage collection unit (GCU) of the solid state drive, the first GCU including N blocks from the multiple blocks;
- compute a parity function of the first GCU;
- identify a data impairment in a first block, the first block being from the N blocks in the first GCU;
- after identifying the data impairment in the first block, copy content from the first block to a block outside the first GCU, clone the first block with the data impairment, and remove the first block from the first GCU;
- determine whether the clone of the first block is added to the first GCU;
- upon determining the clone of the first block is not added to the first GCU, recompute the parity function;
- and
- upon determining the clone of the first block is added to the first GCU, bypass recomputing the parity function for the first GCU.
An apparatus comprising:
- a solid state storage drive configured for incorporation into a data center or data cloud environment, the solid state drive comprising multiple flash memory cells divided into multiple blocks;
- and
- a controller to:
- identify a first garbage collection unit (GCU) of the solid state drive, the first GCU including N blocks from the multiple blocks;
- compute a parity function of the first GCU;
- identify a data impairment in a first block, the first block being from the N blocks in the first GCU;
- after identifying the data impairment in the first block, copy content from the first block to a block outside the first GCU, clone the first block with the data impairment, and remove the first block from the first GCU;
- determine whether the clone of the first block is added to the first GCU;
- upon determining the clone of the first block is not added to the first GCU, recompute the parity function;
- and
- upon determining the clone of the first block is added to the first GCU, bypass recomputing the parity function for the first GCU.
A method of a storage system comprising:
- identifying a first garbage collection unit (GCU) of a solid state drive comprising multiple flash memory cells divided into multiple blocks, the first GCU including N blocks from the multiple blocks;
- computing a parity function of the first GCU;
- identifying a data impairment in a first block, the first block being from the N blocks in the first GCU;
- after identifying the data impairment in the first block, copying content from the first block to a block outside the first GCU, cloning the first block with the data impairment, and removing the first block from the first GCU;
- determining whether the clone of the first block is added to the first GCU;
- upon determining the clone of the first block is not added to the first GCU, recomputing the parity function;
- and
- upon determining the clone of the first block is added to the first GCU, bypassing recomputing the parity function for the first GCU.
Dependencies are inferred from the claim text.