RE: rman backup to disk, mismatch in amount backed up to each cha nnel

I fiddled with this a while back. I believe you'll find that maxpiecesize will limit how large an actual file will become (handy if you're trying not to exceed 2GB). Maxsetsize will limit how large a set is (which can have multiple files). Limiting the set size probably won't help since that's related to the number of files per set, which is why the actual set size may vary. I don't think there is any restriction on multiple sets per channel. Not sure anything can be done automatically to balance the size of each channel's destination other than what has already been suggested. However, I do believe that RMAN tries to balance the amount written per channel, so you could try a finer granularity to your backup. Something like filesperset = 1 might work. There may be a disadvantage in speed of backup, but ??

At 09:32 AM 10/22/2004, Stephen.Lee_at_DTAG.Com wrote:

>A suggestion with no idea if it will work with disk drives.
>Try fiddling with the number of channels in conjunction with the
>maxpiecesize parameter.
>
>allocate channel ch1 type disk maxpiecesize=5000M format 'yada yada';
>allocate channel ch2 type disk maxpiecesize=5000M format 'yada2 yada2';
>allocate channel ch3 type disk maxpiecesize=5000M format 'yada yada';
>allocate channel ch4 type disk maxpiecesize=5000M format 'yada2 yada2';
>
>etc. etc.
>--
>http://www.freelists.org/webpage/oracle-l

Andy Rivenes
Email: arivenes_at_llnl.gov

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