Abstract: Rather than use one long folding operation to fold data from single-level cell (SLC) blocks into a multi-level cell (MLC) block, a storage system uses a multi-stage folding operation. By breaking up the folding process into stages, SLC blocks involved in an earlier stage can be released prior to a subsequent stage being performed. This can increase performance of the storage system by releasing SLC source blocks sooner and reducing an SLC block budget requirement.

Abstract: Technology is disclosed herein for multi-stage data compaction. In a first data compaction stage valid data fragments from source erase block(s) are programmed into a destination erase block at two bits per memory cell. In a second data compaction stage additional valid data from the source erase block(s) is programmed into the destination erase block at two bits per memory cell. In this second stage, the same physical pages of memory cells in the destination erase block may be programmed such that each memory cell in the destination erase block is programmed to four bits.

Abstract: Rather than use one long folding operation to fold data from single-level cell (SLC) blocks into a multi-level cell (MLC) block, a storage system uses a multi-stage folding operation. By breaking up the folding process into stages, SLC blocks involved in an earlier stage can be released prior to a subsequent stage being performed. This can increase performance of the storage system by releasing SLC source blocks sooner and reducing an SLC block budget requirement.