Continuous data protection over intermittent connections, such as continuous data backup for laptops or wireless devices

At least one computer-readable storage medium encoded with instructions for tracking modifications made to data objects stored on a portable device that includes a file system and a continuous data protection component configured to monitor modifications to the file system, the method comprising:

• in response to determining that the portable device is not connected to an external data storage location, at the portable device:
• determining information associated with a modification made to a data object stored on the portable device,
• further comprising:
• monitoring a modification to a data object on the file system, wherein the monitoring is performed by the continuous data protection component;
• and
• storing the associated information in a data structure,
• further comprising:
• storing an indication of the modification monitored by the continuous data protection component.

At least one computer-readable storage medium encoded with instructions for controlling a computer system to method of tracking a requested modification to a file on a file system of a computing device, the method comprising:

• receiving an indication of a requested modification to a file on a file system of a computing device,
• wherein the indication is received by a filter driver configured to intercept requested modifications before they are received by the file system of the computing device;
• determining an offset within the file corresponding to the requested modification to the file and a size of the requested modification to the file;
• storing the determined offset within the file and the determined size;
• and
• relaying the first requested modification to the file to the file system.

A computer-implemented method for tracking modifications made to data objects stored on a portable device, the method comprising:

• determining when the portable device is connected to an external data storage location,
• wherein the portable device stores data objects, and
• wherein the external data storage location is configured to store copies of data objects from the portable device;
• and
• when it is determined that the portable device is not connected to the external data storage location, at the portable device:
• receiving an indication of a modification made to a data object stored on the portable device;
• determining information associated with the modification made to the data object;
• and
• storing the associated information in a data structure,
• wherein the data structure is configured to enable retrieval of the associated information from the data structure and to enable determination of the modification made to the data object based on the associated information;
• wherein the portable device includes a storage device having blocks, the data object is a file, the data structure is snapshot,
• wherein receiving an indication of a modification includes receiving an indication of a modification made to a portion of a file;
• wherein determining information associated with the modification includes determining a set of blocks on the storage device corresponding to the portion of the file to which the modification was made;
• and
• wherein storing the associated information includes changing bits corresponding to the determined set of blocks in the snapshot.