Patent ID: 7549032

Claim:
A method comprising: generating an I/O transaction to read data from or write data to memory that is allocated to store data of a first data block of a data volume, wherein the data volume comprises a plurality of data blocks including the first data block; in response to generating the I/O transaction, reading an entry of a map in memory, wherein the map comprises a plurality of entries, wherein each entry of the map indicates whether memories allocated to store data of respective data blocks of the data volume and a point-in-time (PIT) copy thereof, contain identical data; if the entry in the map indicates that identical data is stored in memories allocated to the first data block of the data volume and a first block of the PIT copy, respectively: reading data from memory allocated to store data of the first block of the PIT copy; and allowing the I/O transaction to complete using the data read from memory allocated to store data of the first block of the PIT copy, without first accessing a transaction log associated with the data volume.