NTBACKUP - What does it actually backup?

[ajbritton]

Two questions in one really both relating to NTBACKUP.

1 - When backing up a volume where single instance storage is active, does NTBACKUP copy the single instance copy and all the links, or does it back up multiple copies of the same file?

2 - When backing up a volume where volume shadow copies is active, does NTBACKUP include the shadow copies along with the original data. If the shadow copy is on another volume what then?

Knowing the answers to these questions helps me work out how much life is left in the old DDS3/4 systems out there (I'm guessing not much though!)

[ajbritton]

OK, after a bit of reading I think I know the answer to question 2, but if anyone knows better, please tell me.

If you enable ShadowCopies on a volume, then when that volume is backed up, backup simply backs up the most recent shadow copy. By default, shadow copies are created at 0700 and 1200 hours every weekday. I assume from this that any work done on Friday afternoon (not much, I know) will not be included in the Friday night backup. If your system goes up in smoke over the weekend, I guess you lose all the drunken nonsense you created after Friday lunchtime in the pub. In a disaster recovery scenario, then, if the entire volume had to be recreated from a backup, all the shadow copies would be lost, as they are not included in the backup.