1. A method, comprising: determining a state of a file system; reading a table associated with the file system, including reading a plurality of block numbers associated with a plurality of files in the file system, the table being stored in a storage, wherein the plurality of block numbers includes a block number and another block number; determining whether each of the plurality of block numbers exists in a reconstruction map being created in a system memory; modifying the reconstruction map; obtaining a hash value associated with each of the plurality of block numbers; reading a plurality of data blocks from a disk using the plurality of block numbers; and constructing a deduplication metadata in the system memory using a read of the plurality of data blocks.