Does a failed backup job reset bits?

[Zotigo]

Hi, I was wondering if someone could help me understand how it works with failed jobs in Veritas. If I ran a FULL backup last week and then ran it again today with no overwrite protection on media and the new FULL backup fails during the process somewhere in the middle. Would the last week's backup still be good or after having been overwritten with this failed backup job today, it is good as nothing?
Same question with DIFF backup jobs. If one failed yesterday, would the one scheduled to run today have the data from day before yesterday too or just the data after the failed one?

Many thanks in advance!

Kind regards,
Zotigo

 

[Spirit]

If your talking DAT / DLT tape then think overwriting a non fast forwardable VHS tape.

You record the episode one of Dr Who last week.
This week you start recording episode two from the beginning of the tape but the tape stops half way through.

So half of last weeks has been overwriten and you won't be able to access the second half without getting fancy.

Also since the recoding failed the catalouge wasn't written so you won't be able to watch the first half of this weeks either.

Iain

 

[Zotigo]

Thanks Iain but Wow, what a mess. But is it also true in case of USB hard disk?