Re: Configure RMAN to write to multiple drives simultaneously

From: Howard J. Rogers <howardjr2000_at_yahoo.com.au>
Date: Thu, 15 May 2003 22:06:03 +1000
Message-ID: <CdLwa.34827$1s1.505436@newsfeeds.bigpond.com>

I don't know about the specifics of your MML, but...

"Steven L. Sesar" <ssesar_at_mitre.org> wrote in message news:3EC2E221.3060304_at_mitre.org...
> Hi,
>
> I'm not sure that this is the place to post this question, however, I'm
> wondering if, and how to configure RMAN, both 8i/91, to write backups to
> multiple drives simultaneously.
>
> Allocating multiple channels does nothing more than write to one channel
> at a time.

That should not be the case.

If you do this:

allocate channel d1 type DISK;
allocate channel d2 type DISK;
allocate channel d3 type DISK;

backup
 format '/bing/bong/blah/xxx' (database);

...then yes, the backup is serialised.

But if you do this:

allocate channel d1 type DISK;
allocate channel d2 type DISK;
allocate channel d3 type DISK;

backup
 filesperset 5
 format '/bing/bong/blah/xxx' (database);

... then it should be parallelised.

The key (in 8.0 and 8i, anyway) was to ensure that there was an explicit limit set on the number of files a channel could process, and that would kick the other channels into taking (simultaneous) part. Otherwise, in the first example, the entire backup would be undertaken by channel 1.

Maybe that has something to do with your issue?

Regards
HJR
>
> The MML I am using is Netbackup, and I'm pretty certain that it's pice
> is configured correctly.
>
> Thanks,
> Steve
>
Received on Thu May 15 2003 - 07:06:03 CDT