Dynamic wear leveling addresses the problem of a limited number of Erase cycles for a given block.
动态平均读写解决了块的Erase周期的次数限制。
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Recall that flash devices are consumable parts: You can perform a finite number of Erase cycles on each block before the block becomes bad (and must therefore be tagged by bad block management).
Here's why this could happen: the metadata update would erase any reference to the original data block(s), but would point to data block(s) on disk that were never filled with data.