In one aspect, a method includes selecting a C-module; sending a write from a host to the selected C-module; selecting a D-module to commit a page related to the write; selecting a R-module to transmit data from the write to the target; writing the data from the write to target location; and writing the data to an address-to-hash table after acknowledgement that the data has been written to the target location and after the D-module acknowledges that the page is committed.