Backup multiple copies in policy vs Vault

[terryd3]

Using NBU 7.6.0.1 we have always used vaulting to create off-site backups, but are starting to have problems with how long it takes for duplication to complete.  Now we are considering creating multiple backups in the policies instead of using duplication to create our off-site tapes.  My question is will backups take twice as long since it is writing everything to tape twice?

[RamNagalla · Accepted solution]

1) if you are using traditional license you need additiional license to perfrom the lnline tape copy(mulitple copy option from policy schedule)

2) this require to use additional resources at the time of backups to get the another copy..(tape dirves/resoureces).

so i recommend you to use the SLP  to achive the duplication  requirement  SLP is more intelligent than the inline tape copy and also Vault.

as you already in 7.6, you can also schedule the SLP duplications...

[Marianne]

Actually, no additional license needed for inline tape copy.... (used to be the case many years ago...)

As a matter of interest, NetBackup Vault Administrator's Guide  recommends inline tape copy, rather than doing post-backup duplications. See Chapter 7 - Creating originals or copies concurrently.

Inline tape copy may need additional tape drives - if you were previously using all available tape drives for backups, you will only  be able to use half of the drives for backups and rest for the second copy.

If media server has enough resources to keep all tape drives streaming, you will see no difference in speed. Both copies will complete in the same time it used to take to backup one copy.

Be sure to go through Multiple copies (schedule attribute) section in NetBackup Administrator's Guide, Volume I  , then start with small amount of policies as test.
Take note of time to complete before and after the change. 
If performance is acceptable, config some more policies.
Keep record of performance.
When you get to a point that backups cannot complete within backup window. revert back to point where performance and backup window was okay. 
The rest of policies can now use vault... Be sure to carefully check selection criteria so as not to duplicate inline policies.

Hope this helps.

[mph999]

In-line tape copy will take longer than a single copy, as the data is not sent at the same time.

bptm is a single-threaded process, so it sends the same data block, first to one tape drive, then the other,

I honestly don;t know how much longer it will take, as I've never compared the two, but as it's simple to set-up why not give it a go ...

[Marianne]

I agree - I you need to test it.

I have tested it in small environment and have seen it completing in more or less the same time. Maybe couple of seconds difference.
You will see 3 jobs in Activity monitor - a parent job and 2 child jobs doing the writing.
The 2 jobs will run at the same speed.

We had a customer who used to run inline copy on all backups with good results. Until the environment became too big and resources became a problem...

[terryd3]

Thanks for the replies.  It sounds like in-line copy will take longer and we can't buy additional tape drives at this time.  We will continue to use Vault for now.