Backup for the Personal Terabyte

Student: Zack Kurmas

Protecting File Systems: A Survey of Backup Techniques
Proceedings Joint NASA and IEEE Mass Storage Conference, March 1998.

To provide high availability, the Personal Terabyte will include disk array redundancy techniques. These features will protect the array from disk, power-supply or other component failures.

A common use of backups is to restore individual files that were accidentally deleted by a user. Keeping file system snapshots on-line can eliminate the need to use traditional backups for this purpose.

However, backups will still be required to protect against site disasters such as earthquakes or fires. Traditional backups are likely to become more difficult over time, as disk capacities increase at a higher rate (60% per year) than disk bandwidth (40% per year). Over time, it will take increasingly long to read the entire contents of a disk. Traditional full backups supplemented by frequent incremental backups are likely to become unworkable.

We are evaluating the use of innovative backup techniques. In a recent paper published in the Joint NASA and IEEE Mass Storage Conference, we surveyed and classified existing backup techniques and identified desriable characteristics for backup in the Personal Terabyte system: