Can Netbackup choose LTO2 and LTO3 tape media to use in certain backup policies?

[W_M_Wong]

Dear all,

Currently, I am upgrading our tape libarary from LTO2 to LTO3 tape drives.

I still want to use LTO2 tape media in the LTO3 tape library for certain backup policies.

Can I configure Netbackup version6.0 able to choose LTO2 tape media for certain backup policies and LTO3 tape media for the rest of the backup policies.

The new tape library will consist only LTO3 tape drives.

Any help is greatly appreciated.

Thank you.

[Yasuhisa_Ishika]

Hi Wong,

Why don't you configure volume pools for each; one is for LTO 2 and another is for LTO 3?

Did you configured new drives as hcart3? And media type of LTO 2 tapes is hcart2?

If so you have to reconfigure drives as its type hcart2.

[W_M_Wong]

Hi,

Thanks for the information.

Let's say I have one media server backing up HPUX and Windows Clients.

And I want Windows Client to use only LTO2 tape media and HPUX clients using only LTO3 tape media.

If I create two pools for Windows and HPUX respectively, what about the scratch pool?

I can put more than enough LTO2 and LTO3 tape media in Windows and HPUX pools, but if any of the tape expired, it will still go back to scratch pool and I have to manually move it to the respective pools before the tape is wrongly used for the next backup.

[Poon_William]

Hi Wong,

  I think I have the same query as you as I will be upgrading all tape drives in my Library from LTO2 to LTO3.

Hi  All,

   Assume the following scenario,

1. Upgrade all tape drives to LTO3 (Remove all LTO drives)

2. Create new Storage Unit with hcart3

3. Add new hcart3 medias into scratch pool. ( so now the Scratch Pool will contains both LTO2 and LTO3 medias)

Question:

1. When the backup run and require a new tape, NB will try to pick up a free tape in Scratch Pool. Will it pick up a LTO 2 tape (This is a Hcart3 storage unit) ?

2.  If NB do pick up a LTO2 tape, What will the backup speed base on ? It will be base on LTO2 or LTO3 spec ?

3. Same question as Wong. If I set up a pool that will use all LTO2 medias. When the images on these LTO2 expired, it will go to Scratch Pool. How do I control that so that it will move back to the original pool instead of Scratch Pool ?

Rgds,

WP

[AndreaBolongaro]

Hi wong,
this may be useful:

VERITAS NetBackup (tm) best practices guide on migrating to or integrating
new tape drive technologies in existing libraries.

http://support.veritas.com/docs/281314


Hope it helps,

[Chia_Tan_Beng]

Hi Wong,

 I think the document referred by Andrea is a good starting point. However if you're going to replace all the drives to LTO-3 without leaving a single LTO-2 drive, I doubt you can create a storage unit with HCART2 (because there's no such definition in the library setup of the media server).

 If there's none HCART2 drive left, moving the desire media to the desire pool maybe the option but it lack the automation (automatically pick from Scratch pool). And you have to wait until the media expire and re-define its media type definition. So do consider leaving one LTO-2 drive behind (can be use for restoring purpose as well) if you can affort.

 If leaving a LTO-2 drive is out of question, you may consider defining the new drive with same drive type definition (check with Symantec first). That's what we did when we upgraded from LTO-1 to LTO-2. The advantage is that you still able to leave the LTO-2 cartridges in library for restoration and for backup. The set back is that NB can't differentiate if it's LTO-2 or 3 (but LTO-3 can r/w LTO-2 tape, so you can move LTO-2 tape into Window backup pool manually). That was enough for us as we continued to use the 'old tapes' for slow clients while slowly retire them in phases. 

 Something we observed, when LTO-2 drive writes to LTO-1 tape, although its running at de-graded mode, its still faster than LTO-1 drive. You may want to benchmark this between LTO-2 & 3. Have fun.

[Chia_Tan_Beng]

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Poon William wrote:

Question:

1. When the backup run and require a new tape, NB will try to pick up a free tape in Scratch Pool. Will it pick up a LTO 2 tape (This is a Hcart3 storage unit) ?

2.  If NB do pick up a LTO2 tape, What will the backup speed base on ? It will be base on LTO2 or LTO3 spec ?

3. Same question as Wong. If I set up a pool that will use all LTO2 medias. When the images on these LTO2 expired, it will go to Scratch Pool. How do I control that so that it will move back to the original pool instead of Scratch Pool ?

Rgds,

WP

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1. I haven't try that but if your media type for LTO-2 tape is still maintain as HCART2, I believe its NOT going to be picked up.

2. If you changed LTO-2 tape to media type HCART3 and is picked up, the drive would run at degraded mode (i.e. based on LTO2 spec). However my experience on LTO-2 drive writing to LTO-1 tape is faster (refer to my previous reply) and I feels that this may applies to LTO-3 drive as well.

3. If the tape was previously manually moved to the pool, when it got expired, it won't move back to scratch pool (Hi NB6 gurus, please correct me if I'm wrong). That's no way to control it but once you move into the desire pool manually, the next time it expire, it'll stays in that pool.   

[Yasuhisa_Ishika]

>If the tape was previously manually moved to the pool, when it got expired, it won't move back to scratch pool

 Yes, that's correct - if previously manually moved.

 And we can control kick-back behavior with RETURN_UNASSIGNED_MEDIA_TO_SCRATCH_POOL(vm.conf or nbemmcmd). But this affects all media in NetBackup.

[Chuck_Stevens]

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W M Wong wrote:

Dear all,

Currently, I am upgrading our tape libarary from LTO2 to LTO3 tape drives.

I still want to use LTO2 tape media in the LTO3 tape library for certain backup policies.

Can I configure Netbackup version6.0 able to choose LTO2 tape media for certain backup policies and LTO3 tape media for the rest of the backup policies.

The new tape library will consist only LTO3 tape drives.

Any help is greatly appreciated.

Thank you.

---

I had this same question, posed it to Veritas support, and the answer was "No."

The LTO3 tapes and drives are all "hcart3", so the Storage Units will also be hcart3.  You can load the LTO2 tapes into your library, but the storage units will never call for one, and there is no way to specify hcart2 for a policy or storage unit.

If you find a way around this limitation, I'd love to hear it.  I've got a shelf full of unusable LTO2 tapes just taking up space.

[Chuck_Stevens]

Answers inserted in bold:

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Poon William wrote:

Hi Wong,

  I think I have the same query as you as I will be upgrading all tape drives in my Library from LTO2 to LTO3.

Hi  All,

   Assume the following scenario,

1. Upgrade all tape drives to LTO3 (Remove all LTO drives)

2. Create new Storage Unit with hcart3

3. Add new hcart3 medias into scratch pool. ( so now the Scratch Pool will contains both LTO2 and LTO3 medias)

Question:

1. When the backup run and require a new tape, NB will try to pick up a free tape in Scratch Pool. Will it pick up a LTO 2 tape (This is a Hcart3 storage unit) ?

No. It will only pick LTO3 tapes. The Storage Unit is hard-coded for hcart3 density tapes, not hcart2.

2.  If NB do pick up a LTO2 tape, What will the backup speed base on ? It will be base on LTO2 or LTO3 spec ?

If by some miracle a LTO2 tape is selected, then it will run LTO2 speeds (the drives usually are backward compatible).

3. Same question as Wong. If I set up a pool that will use all LTO2 medias. When the images on these LTO2 expired, it will go to Scratch Pool. How do I control that so that it will move back to the original pool instead of Scratch Pool ?

If the tapes start out in the original pool, they won't go back to Scratch.  Only tapes that were originally pulled from Scratch will go back there.

Rgds,

WP

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[Chuck_Stevens]

Hmm.  Reading the above-referenced white paper (which I have never seen before), there might be an answer: Use the vmchange command to modify the media type of the LTO2 tapes from "hcart2" to "hcart3".  I'll have to try this out, see if it works.

[Poon_William]

Hi All,

     Glad  to see so many useful suggestions. Thank to Wong for bringing up the subject.

     As Stevens has mentioned, I will have to define the new LTO3 drives in the new storage units as Hcart3 as NB will only allows me to select Hcart3.  When I re-load the recycled LTO2 medias, I will have to change the media type to Hcart3 so that the new drives will pick them up ( Hi Stevens, hope you can update us on your test results). 

   However, I still have one concern. If now I change all drives to LTO3 and in situation when I need to restore certain data in the offsite tape. I will load the tape into the library and change the media type to Hcart3. Will NB have problem to read the data in the tape as I have already change the media type ?

Rgds,

WP   

[Yasuhisa_Ishika]

> Will NB have problem to read the data in the tape as I have already change the media type ?

 Now I have lesson of Enterprise Vault in Symantec Japan right now and can't verify in my test env.

But I'm sure there are no problem importing the volume those media type changed.

[Chuck_Stevens]

It is working.

Since my old LTO2 tapes had not been loaded before, I set up a barcode rule to import the tapes as HCART3, and to send them to a specific volume pool (not Scratch).  Ran a test backup and it grapped the LTO2 tape and started writing.

Easy as cake.

Makes me wonder why, when I opened a support ticket for this last year, the Veritas guy didn't know this simple answer...

[Jeff_Sundin]

I have an environment that started with LTO, then migrated to LTO2, and now is implementing LTO3.  During the first migration, the first administrator simply left all configurations as HCART and it is able to read LTO and LTO2 tapes. 

I was given a new library (LTO3) to get working and only had LTO2 tapes to use for now.  I set it all up as HCART again and it picks up and writes all the LTO2 tapes just fine. 

Jeff

[Chuck_Stevens]

I think it's all the same.  So long as the drives, storage units, and media all match, it should work.