Duplicating for standby

On the start I have a target database configured with OMF and specified unique db name. On the standby side I created an instance, started it and that's it. Oh, yeah - I copied password file from primary side to be able to connect to standby and configured listener with GLOBAL_DBNAME, which allows for registering a service for use in tnsnames.ora on both hosts. Of course I specified proper entries in tnsnames.ora as well.
There are possible many configurations for this duplication - combinations of a target database, a standby database and a catalog - of course a standby one is a must, but the rest is optional and may be avoided, although it complicates the matter a little. I choose to use additionally to standby database also active target database. This avoids the trouble of applying all the redo logs from last backup.

RMAN> DUPLICATE TARGET DATABASE FOR STANDBY FROM ACTIVE DATABASE;

First failure: the command failed with ORA-17628: Oracle error 19505 returned by remote Oracle server on primary and ORA-19505: failed to identify file "/oracle/oradata/ZABBIX/controlfile/o1_mf_855ys7j8_.ctl"
ORA-27040: file create error, unable to create file as I did not create path for controlfile (so now mkdir -p /oracle/oradata/ZABBIX/controlfile/o1_mf_855ys7j8_.ctl).

Second start and failure:

RMAN-03002: failure of Duplicate Db command at 11/13/2012 10:14:19
RMAN-05501: aborting duplication of target database
RMAN-03015: error occurred in stored script Memory Script
ORA-06550: line 1, column 17:
PLS-00201: identifier 'DBMS_RCVCAT.GETDBID' must be declared
ORA-06550: line 1, column 7:

I found at http://blog.csdn.net/tianlesoftware/article/details/6232292 that it is due to not specifying nocatalog when connecting with rman. And that really helped.
Third try and this time I moved much ahead - I was wrong with assuming the online logs will be created according to the db_create_file_dest (so I should set db_create_online_log_dest_n at least to overcome this). However this time duplication is going forward - the data files are created according to the plan.
Because copy is done with backup as copy reuse datafile X auxiliary format new then no useless copying to storage local to primary and all bytes goes directly to the standby files, which is nice

To finish the standby I need now to add standby log files (though this is optional) and set log_archive_dest_state_2 to enable. The managed standby is already run by the duplicate command. One may want to switch this to recovery using current logfile.