An apparatus in one embodiment comprises at least one processing device comprising a processor coupled to a memory, with the processing device being configured to obtain content-based signatures for respective data pages of at least one write operation, to send the content-based signatures to a content addressable storage (CAS) system, and to receive from the CAS system information indicating for each of the content-based signatures whether or not the corresponding data page is present in the CAS system. Responsive to the information received from the CAS system indicating that one or more of the corresponding data pages are not present in the CAS system, the processing device sends the one or more corresponding data pages to the CAS system. The processing device illustratively comprises a host device coupled to the CAS system over a network.