Patent ID: 7797358

Claim:
A method, comprising: storing a journal history of write transactions in a continuous data protection system, the journal history of write transactions comprising: a do data stream comprising data for writing in a storage system; an undo data stream comprising data that is overwritten in the storage system; a do metadata stream comprising a first pointer to an offset in the do data stream where the data for writing in a storage system is located; an undo metadata stream comprising a second pointer to an offset in the undo data stream where the data that is overwritten is located; compressing data prior to entry in the do data stream; storing compression information in the do metadata stream for the do data stream entry; accessing the data for the entry in the do data stream; examining the do metadata stream for the entry; decompressing the do data stream entry using the compression information in the do metadata stream; and writing the decompressed data to storage.