Duplication 1 drive

[Vicente_Fukuda]

Hi there

2 questions about duplication:

Is possible to duplicate a set of images in a volume group with only ONE drive? Or should I have to duplicate to disk and then another duplication to another tapes?

If this is possible, how can I automate this actions? a policy or with a script?

Regards and thanks

Vicente

[Dion]

If you only have one tape drive and the first copy is already sitting on tape, you will have to go with option of duplicating to disk firts (Copy 2) and then back onto tape (Copy 3).  You can then expire the copy that you don't need e.g. Copy 2.

The reason that you will have to do this is that the process of duplicating needs a read copy and the write destination to be available at the same time.  In the case that your first copy is on tape and the destination is on the same tape drive, you won't be able to do this as one step.

To automate this whole process (I'm guessing that you want the final solution to have two copies on tape) you can test out the following - haven't tried it myself but should work in your case where you only have one drive.

1. Set you DSSU up as a temporary staging storage unit 

2. Set your backup policy to write multiple copies inline - one copy to your disk and the second to tape (e.g. ONSITE pool) at the same time.

3. Set up your DSSU staging schedule to duplicate to tape at a time when the backups aren't running (this will be to the e.g. OFFSITE volume pool).  Because you only have one tape drive, you need to make sure that the correct (or new) tape in in the drive at the time it starts and not the tape with the first copy.  If the pools are different the duplication won't run and could fail.

Because the DSSU is set up as a temporary staging area, NetBackup will prune backups on the DSSU that have already been duplicated by the staging schedule.

Hope this helps

[ekay]

Would it be possible to duplicate two sets of the original backup if there are 3 tape drives?

[sdo]

You can't create multiplexed duplications of non-multi-plexed images/backups.

But you can duplicate a single multi-plexed image/backup to a non-multi-plexed media.

As for whether you can take two different multi-plexed backups from different multi-plexed media, and multi-plex to a third media - I really don't know, but I doubt it.

But, you should be able to duplicate a single multi-plexed tape to another multi-plexed tape, as long as you duplicate all of the images in the media-set (one or more images on one or more media).  I don't know if you can just select two images (say out of three that were multi-plexed) and just multiplex the two back together (effectively dropping the third image) - not sure.  Test and found out.  Good luck.

[sdo]

I've just learnt that v6.5.x now supports duplication from a storage unit on one media server to a different storage unit on a different media server (across the network of course).

Now I'm going to test to see whether the target storage unit can be a Storage Lifecycle Policy (storage unit) on the remote media server.

[ekay]

i am also try to find out if different retention period can be set between the original tape and the duplicated tape.  If you have some info abt this, pls help to post it here. Else when i find out, i would post it here too. Thanks in advance.

[Dion]

Firstly, using 3 tape drives, you will be able to do what you need to do, especially if you have disk as well - here are some examples.

Copy 1 - disk.  Duplicate copy 2 and 3 to tape at the same time.

Copy 1 and 2 to tape at the same time

Copy 1 to tape. Duplicate copy 2 and 3 at the same time etc. etc.

ekay - regarding your question about having different retention periods, yes you can if you are running Vault.  Take a look at the following scenario that I used to run - I had all my duplication covered by one Vault session using retention mapping.  Under Host Master server, your server settings, you can modify the retention periods.  Afterwards, in Vault, you set retention mappings for the duplicated copy

Here's the example.

retention 10 = 2 weeks (this was for my Sun - Thu daily inc backups)

retention 11 = 2 weeks (this was for my Fri weekly full backups)

retention 12 = 2 weeks (this was for my monthly full backups)

retention 20 = 4 weeks (this will be set up to map retention 10)

retention 21 = 3 months (this will be set up to map retention 11)

retention 22 = 7 years (this will be set up to map retention 12)

In the vault properties you can set up retention mapping where you map 10-20, 11-21 and 12-22.  When vault runs, all backup images that it finds that are retention 10 (2 weeks) it will duplcate onto tape as retention 20 (4 weeks) and likewise for the others.

All of your original backups (copy 1) have different retention index numbers but have the same retention period (2 weeks).  You just need to make sure that you duplicate the data to tape withing the 2 weeks.

Hope this helps

[sdo]

Ekay, yes the duplicate image can have a different retention from the source image.  They remain the same image, but the copy/copies can have different retentions.

[Vicente_Fukuda]

Hi

Thanks for replies.

Regards