The limited erase cycles of a block leads to the lifetime issue of SSD. One of
studies is the healing technology, which is achieved by heating the cell and restore
its state. To prolong the lifetime at most, one should even the healing count across
all blocks. However, similar to erase operation, healing incurs extra writes. In this
paper, we provide a healing scheme from a different perspective. We unleveling
the usage between blocks and postpone the migration until certain point. Saved
the copies by avoiding migration for leveling the heal count in early stage, the
overall copies are therefore reduced. Through evaluation, the lifetime extension
is up to 18% due to the great migration reduction. Also, it reduces the average
heal time by 20 % at best.

The limited erase cycles of a block leads to the lifetime issue of SSD. One of
studies is the healing technology, which is achieved by heating the cell and restore
its state. To prolong the lifetime at most, one should even the healing count across
all blocks. However, similar to erase operation, healing incurs extra writes. In this
paper, we provide a healing scheme from a different perspective. We unleveling
the usage between blocks and postpone the migration until certain point. Saved
the copies by avoiding migration for leveling the heal count in early stage, the
overall copies are therefore reduced. Through evaluation, the lifetime extension
is up to 18% due to the great migration reduction. Also, it reduces the average
heal time by 20 % at best.

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