Data deduplication techniques may use a fingerprint hash table and a backend location hash table in connection with performing operations including fingerprint insertion, fingerprint deletion and fingerprint lookup. Processing I/O operations may include: receiving a write operation that writes data to a target logical address; determining a fingerprint for the data; querying the fingerprint hash table using the fingerprint to determine a matching entry of the fingerprint hash table for the fingerprint; and responsive to determining that the fingerprint hash table does not have the matching entry that matches the fingerprint, performing processing including: inserting a first entry in the fingerprint hash table, wherein the first entry includes the fingerprint for the data and identifies a storage location at which the data is stored; and inserting a second entry in a backend location hash table, wherein the second entry references the first entry.