RMAN detects corrupt controlfile - how to determine which one

Oracle 8.1.7.4 on Windows 2000.

We use RMAN for database backups, and the backup has failed due to a = corrupt controlfile.
We have 3 controlfiles, each on separate disk controllers, so I can = recover it (& yes they're also backed up),=20

but Metalink note 148049.1 says to use a trial and error approach to = determine which control file is the corrupt one: ie shut down DB, comment out 1 control file, restart and see if a backup = works & repeat

I've done this before and you get there, but is there a faster way (ie = reduce number of database outages) to tell from the alert log error = information or some other way which actual control file is corrupt:

Alert log extract

Corrupt block relative dba: 0x00000412 (file 0, block 1042) Bad header found during backing up controlfile Data in bad block -
 type: 21 format: 2 rdba: 0x00000411
 last change scn: 0xffff.0007a002 seq: 0x1 flg: 0x04  consistency value in tail: 0x322a1501
 check value in block header: 0x459f, computed block checksum: 0xd814  spare1: 0x0, spare2: 0x0, spare3: 0x0

Thanks,
Bruce Reardon

NOTICE
=20

This e-mail and any attachments are private and confidential and=20 may contain privileged information.
=20

If you are not an authorised recipient, the copying or distribution=20 of this e-mail and any attachments is prohibited and you must not=20 read, print or act in reliance on this e-mail or attachments.
=20

This notice should not be removed.

--
http://www.freelists.org/webpage/oracle-l