How to ensure two copies use same two tapes until full

[fregal]

Hi,

Using NBU 7.5.0.4 Windows master and Linux media servers.  

I want to create a user backup policy with one schedule that will write two copies.  The tapes that are written will be in a volume pool that is only accessed by this policy.  I have been asked simply to ensure each copy of the backup is written to two tapes.  I will let NBU assign scratch tapes to the pool.  The backups are to be retained for 10 years.

So if I start with no tapes in the pool, on night 1 I expect two tapes to be added to the pool, tape0001 for copy 1 and tape0002 for copy 2 as per the schedule.  The tapes will be nowhere near full, in fact I expect to get more than one month's worth onto each tape.

Can I be sure that on night 2, tape0001 will be used for copy 1 and tape0002 will be used for copy 2 of the backup?  Can I be sure that this will continue until both tapes are full, when tape0003 and tape0004 will be pulled into the volume pool from scratch?

Also, is there a flag to say do not span multiple tapes with one image?

thanks!!

[Will_Restore · Accepted solution]

Set up two pools, say Copy1 and Copy2 (or whatever), set the schedules to write to specific pools,

then set Maximum number of partially full media to 1 for each pool

http://www.symantec.com/business/support/index?page=content&id=TECH69376

Also, is there a flag to say do not span multiple tapes with one image?

When a tape fills up it's going to span volumes, unless you have no Scratch pool and the job would fail.  Not the best practice.

[fregal]

Thanks Will.  Perhaps I need to rephrase my question...

Do I care whether copy 1 on night 2 goes on tape 1?  Both copies created by the schedule will presumably be exactly equivalent, so as long as the copies do not go on the same tape in one night, then there is no issue.

I could, in this case, create one pool and set the MPF to 2.

Any reason why this would not work?  I don't want to introduce extra complexity for no gain :)

[Will_Restore]

NetBackup Schedule works with volume pools not individual tapes.  With multiple active tapes in a given pool there is no guarantee which tape will be used, or that both images will not be written to the same tape (unless you are doing simulteanous writes - I've not tried that). 

I think it would be less complex to backup to one tape and then duplicate to another.  You don't indicate what version NetBackup but SLP - Storage Lifecycle Policy - would be the way to go. Read through that section in the Admin Guide. 

[Mark_Solutions · Accepted solution]

You could set retention level 10 to 10 years and retention level 11 to 10 years .. use RL10 for one copy and RL11 for the other copy .. then set maximum partially full media of your pool to 1.

That keeps all of the first copies on one tape and all of the second copies on the other tape .. yet uses the same pool, makes sure the tapes are filled up and both are kept for 10 years...

Just a thought