Restore standby controlfile

# on primary
alter database create standby controlfile as'/oraexport/cfd_stby.ctl';

# on secondary
show parameter controlfile;
shutdown abort;
scp new standby controlfile from primary
startup mount

rman
connect target /
CATALOG START WITH '/sl02cfd/oradata1/S02CFD/datafile';
SWITCH DATABASE TO COPY;