The illustration is my attempt to describe the process for block level CDPA with 30,000 feet view. The concept is similar to versioning & journaling and database transaction logs. The main differences from other CDPA solutions are database driven CDPA tracker and removing the time-slice concept.
I believe a combination of file and block level CDPA can achieve optimal level of continuous data protection (CDP) desired by users. I hope CDP vendors wouldn't muck up the segment by positioning superiority of one level over another like virtualization or SAN vs. NAS.
It is not amusing anymore explaining that SAN and NAS are complementary technologies not 'competing' solutions.
Anyway, enough about CDP, it is time to get back to developing requirement definition for a large archive (2PB to 10PB) and creating a backup tutorial.