Patent ID: 8296264

Claim:
A computer system operable to provide online continuous data protection, the system comprising: a processor; a memory coupled to the processor and storing instructions to work with a file system; the file system that stores files on a storage media and addresses the storage media using clusters as a minimal addressable unit; a file system driver that services the file system; a list of protected objects, the protected objects being files or directories, with each protected object residing below a protected folder including a first timestamp indicating when protection was enabled for that object and a second timestamp indicating when the object became unprotected; a storage media for storing the file system data, the storage media connected to the file system driver; a filter that monitors changes in the file system and having a set of files that are being monitored; wherein the filter redirects, to backup storage, only portions of files that are being modified prior to the modification, and overwrites those portions with new data; wherein, after a write file request is received, data is written to the file, file changes are copied to dirty pages, and the file changes are written to incremental backup, wherein each file cluster is written to the backup storage only once for every opening of the file, and wherein a new version of each file cluster is written to the backup storage for each time the file is opened; upon user action, the filter providing a rollback to a prior state with the data prior to the modification coming from the backup storage, and unmodified portions of the file coming from the storage media.