To tell RMAN to permit corrupt blocks to be backed up you must use the SET MAXCORRUPT command(note that this goes inside the RUN command);
SET MAXCORRUPT FOR DATAFILE ‘foo’ TO n;
where ‘n’ is the number of corrupt blocks which will be allowed in the backup. However the ‘set maxcorrupt’ command only applies to the rman BACKUP command not the rman COPY command. To work around this problem for the rman COPY command you must modify “recover.bsq”.
Find the line in “$ORACLE_HOME/rdbms/admin/recover.bsq” which looks like this:
and add the following line immediately after that line:
For more information please see metalink note 1069093.6.