Parallelism and RMAN 1

[yeazel]

I have an RMAN script setup to backup an Oracle database to an 'oracle' pool. 2 channels have been allocated and I'm backing up to a Legato server with 2 drives. I was expecting that each channel configured would go to seperate devices, but I'm seeing 2 'sessions' open up on a single drive for the backups. I'd like to split these backups across the drives so I can double my performance. Any suggestions?

Thanks in advance!

Troy

 

[john7]

You could open more channels, this seems to equate to a datastream to Networker. If this is the case your drives in Networker most likely have target sessions set to 4 (this is the default number).

You can also change the target sessions to 1 on the drives in networker. this will force a stream of data to each drive. BUT this does not mean you will get twice the performance you will most likely get the same performance spread acroiss the two drives.

John7

 

[yeazel]

No wonder. Target sessions were set to 10 on each drive. I set the target sessions to 1 and that did the trick for the oracle backups. I did not see a doubling in performance, but it looks like it did improve by ~35%.

 

[edskolnik]

Would you care to let me know how you have the Oracle recovery catalog defined? Do you run a standalone instance of Oracle for your recovery catalog and if so how do you handle the Orcale License? If not what do u do?

Ed Skolnik