Compressed RMAN backup and DeDup?

[Thomas_Schulz_3]

Hello.

My next question ...

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

[Nicolai]

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

[Andrew_Madsen]

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

[Thomas_Schulz_3]

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

@Wolfsbane -> Thx

[Nicolai]

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.

[teiva-boy]

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.

[Nicolai]

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

[Thomas_Schulz_3]

@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]

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.

[Nicolai]

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.