There are many different snapshot methods available, and their requirements all differ.
Chech this document, Table 1-2 on page 33 lists all the snapshot methods available and their requirements.
Veritas NetBackup Snapshot Client™ Administrator’s Guide
http://seer.entsupport.symantec.com/docs/290224.htm
These documents will help you too.
Veritas NetBackup (tm) 6.5 Snapshot Client Quick Start Guide
http://seer.entsupport.symantec.com/docs/290225.htm
Veritas NetBackup (tm) Snapshot Client Configuration
http://seer.entsupport.symantec.com/docs/288300.htm
Enjoy!
Abe