Intel Corporation
ON-SSD-COPY TECHNIQUES USING COPY-ON-WRITE

Abstract:

On-SSD-copy using Copy-On-Write (COW) techniques track indirection updates to the copied data without duplicating the data. In one example, a method involves receiving a copy command to copy data from a source LBA to a destination LBA. An entry in a logical-to-physical (L2P) table corresponding to the destination LBA is updated to refer to the same physical address as the source LBA's entry in the L2P table. Flags in the L2P table are updated to indicate that more than one LBA refers to the same physical address. After updating the L2P table and before copying the data, a token is stored to the storage device. After storing the token, but before copying the data, an acknowledgement can be sent to the host to indicate the copy command is complete. A subsequent write to either the source or destination LBAs trigger a copy of the data.