RMAN Allocate Channel

The code should look similar to what is listed below.

 RMAN> RUN {
 2> ALLOCATE CHANNEL C1 TYPE DISK;
 3> BACKUP DATABASE FORMAT 'D:\BACKUPS\%u';
 4> RELEASE CHANNEL C1;
 5> }

To manually allocate a channel, which is a connection between RMAN and a database instance. Each connection initiates an Oracle server session on the target or auxiliary instance: this server session performs the work of backing up, restoring, or recovering backup sets and copies.
Manually allocated channels (allocated by using ALLOCATE) are mutually exclusive with automatically allocated channels (specified by using CONFIGURE). Manually allocated channels apply only to the RUN job in which you issue the command. Automatic channels apply to any RMAN job in which you do not manually allocate channels. You can always override automatic channel configurations by manually allocating channels within a RUN command.