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Questions on Data Domain DD Boost with Netbackup 7.5

Created: 10 Jun 2013 • Updated: 17 Jul 2013 | 3 comments
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I'm looking for confirmation of my understanding of how DD Boost works with Netbackup 7.5. We are planning to make all large servers media servers with DD boost installed to enable de-dupe at source. 

Is it true that for DD Boost de-dupe at source to work.... 

a) Netbackup media server to be installed (not just the ordinary Netbackup client) along with the dd boost plugin,


b) each media server must have a dedicated storage unit for which it is the only media server enabled/assigned?

As I understand it, without a storage unit dedicated to the target media server, another media server also assigned to the storage unit could step in to backup the first (I have seen this happen - Netbackup DOES NOT favour the 'local' media server). If that happens then the initial transfer of data across the network from the original source media server to the secondary media server will NOT be de-duped but will be a far-from-ideal full transfer of every single last scrap of data. The secondary media server will then de-dupe the transfer between itself and the Data Domain storage box. 

Is this the truth of the matter?

Thanks for any input!

Operating Systems:

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Nicolai's picture

A: True

B: True

"C": True - Even though I believe you can avoid the scenario you are describing using EMM settings and storage server flags, you're plan will work using "out of the box" configuration. And since there no cost related to creating DD storage units it sound like a fine plan (just keep the number of Mtree <14 - it's a EMC recommendation).

How to configure MUST_USE_LOCAL_DRIVE - Must be set on the media server 

Assumption is the mother of all mess ups.

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SteveLaw's picture

Hi Nicolai,

Is MUST_USE_LOCAL_DRIVE the fix for this problem - it will force media servers to always back themselves up, even if there are other media servers enabled for the same storage unit?

There is a setting on the Master server in admin console. But are you saying that the command must also be run against media servers using the nbemmcmd on the command line?


Nicolai's picture

I have verified this setting work using tape drives - so I can't see why it shouldn't't work using data domain or  any other type of storage unit.

I believe there is a fault in the documentation. This setting exist on media server as well (EMM) and it does not work as intended if it's only set on the master server.

Please consider how restore will work as well. Using data domain any media server connetced may serve the restore request if they are connected to the same storage unit.

See :

  • PrefRestore. The storage server is preferred for the read side of restore operations.

  • ReqRestore. The storage server is required for the read side of restore operations.

  • ReqDuplicate. The storage server is required for the read side of duplication operations.

Assumption is the mother of all mess ups.

If this post answered your'e qustion -  Please mark as a soloution.