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Compressed RMAN backup and DeDup?

Created: 20 Mar 2013 | 9 comments

Hello.

My next question ...

Is it for Netbackup possible to DeDup a compressed RMAN/Oracle backup, or not?

Operating Systems:

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Nicolai's picture

How does RMAN compress data ? Is it key or row compression. Is it zlib type ?

Assumption is the mother of all mess ups.

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Andrew Madsen's picture

The simple answer is not it is not possible to. Especially if you multiplez and use multiple channels. Been there done that.

The above comments are not to be construed as an official stance of the company I work for; hell half the time they are not even an official stance for me.

Thomas Schulz 3's picture

@Nicolai -> Our DBA says the Oracke Exadata compress the data and send it to the netbackup ......

 

@Wolfsbane -> Thx

Nicolai's picture

my understanding is that RMAN will uncompress data before sending data to Netbackup (that is what my DBA tell me). You will however need to set RMAN MAXFILESPERSET=1 to obtain a really good de-dupe factor.

Assumption is the mother of all mess ups.

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teiva-boy's picture

My understanding is that ExaData uses a compressed database that is run in memory and flash.  One of Oracle's claims is to reduce storage consumption by 10x.

 

That said, the RMAN outputs are pre-compressed, and cannot be deduped.  You could do a table export, but that would be slower.  Best to just stream the database directly to tape or plain disk.

There is an online portal, save yourself the long hold times. Create ticket online, then call in with ticket # in hand :-) http://mysupport.symantec.com "We backup data to restore, we don't backup data just to back it up."

Nicolai's picture

There may be diffrent Oracle ExaData configurations. I just check our Oracle ExaData cluste and I am seeing a 69% dedupe ratio with a backup size of 1.3TB.

We use FILEPERSET=1

 

Assumption is the mother of all mess ups.

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Thomas Schulz 3's picture

@Nicolai

Are all Exadata backups in your DeDup area? Or do you stage it to the tape?

And how much backup sets are in your DeDup area?

Nicolai's picture

All data go to a PDDO (Symc5020). No data go to tape (YES!!!).

Currently holding  6465349888KB of Oracle data. Retension is 1 month and went in production some weeks ago.

Assumption is the mother of all mess ups.

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Nicolai's picture

On thing more my DBA told me

Compression require a additional license from Oracle.

If the RMAN output was "unique" compare to other RMAN backup it wold not be possible to clone or disaster restore to a non ExaData box.

Assumption is the mother of all mess ups.

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