Chapter 16 of Admin Guide I explains it best.
Administrator's Guide for UNIX,Linux, I http://www.symantec.com/docs/TECH127081
Administrator's Guide for Windows, I http://www.symantec.com/docs/TECH127079
It covers the following topics:
■ About synthetic backups
■ Policy considerations and synthetic backups
■ Types of synthetic backups
■ When to use synthetic backups
■ Synthetic backup jobs create two sets of catalog files
■ Change journal and synthesized backups
■ True image restore and synthesized backups
■ Checkpoint restart and synthesized backups
■ Displaying synthetic backups in the Activity Monitor
■ Logs produced during synthetic backups
■ Synthetic backups and directory and file attributes
■ Using the multiple copy synthetic backups method
■ Optimized synthetic backups using OpenStorage
Hopefully this chapter will answer all your questions.
