Probably one of the most misunderstood aspects of some of the newer disk based backup technologies like OST and PDDO is exactly how you use them as part of your site DR strategy, particularly if your DR domain is separate from your production domain.
Sure, if you have one domain spanning multiple sites you can write your backups to deduplicating disk storage at one site and copy it to another site using optimized duplication but that second site needs to be part of the same NetBackup domain to do that and it’s not much use on its own if you lose the first site and that’s the only place you have a master server.
Of course you could be replicating your catalog to a standby master server at the second site but to do that Symantec says you need clustered master servers on both sites.
In NetBackup 6.5.4 Symantec allows you to write your catalog backups to these newer disk types. You can even duplicate the catalog backup between sites with storage...