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

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.

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