A system and method are described to improve the efficiency of copy-on-write operations in a storage system. A partition mapping table is maintained in a cache memory, where the partition mapping table is used to translate logical partitions into physical partitions. A request is received to write one or more blocks BB to partition PSS, and, upon receiving the request, the pointers in the partition mapping table are interchanged such that data associated with PSS is now associated with PTT. Next, block(s) BB is written to PSS and a read command is issued so that data now associated to PTT is read into the memory and is associated with PSS, except for block(s) BB that was written. In an alternative scenario, the steps of writing block(s) BB to PSS and issuing a read command are performed simultaneously.