US Patent 8990171 Optimization of a partially deduplicated file

The subject disclosure is directed towards transforming a file having at least one undeduplicated portion into a fully deduplicated file. For each of the at least one undeduplicated portion, a deduplication mechanism defines at least one chunk between file offsets associated with the at least one undeduplicated portion. Chunk boundaries associated with the at least one chunk are stored within deduplication metadata. The deduplication mechanism aligns the at least one chunk with chunk boundaries of at least one deduplicated portion of the file. Then, the at least one chunk is committed to a chunk store.