RMAN automatic channel allocation

We use the configure command to automatically allocate channels.  And Automatic channel allocation lets you configure persistent channels for use in all RMAN sessions.

Examples:

--Generic Settings for Automatic Channels
RMAN> configure channel device type disk maxpiecesize 2g;
 old RMAN configuration parameters:
CONFIGURE CHANNEL DEVICE TYPE DISK MAXPIECESIZE 1 G;
new RMAN configuration parameters:
CONFIGURE CHANNEL DEVICE TYPE DISK MAXPIECESIZE 2 G;
new RMAN configuration parameters are successfully stored
 RMAN>
 --Configuring Specific Channels for a Device Type
RMAN> configure channel 1 device type disk format '/disk1/%U';
RMAN> configure channel 2 device type disk format '/disk2/%U';