We have a customer which have all they core business database on RAC over Windows OS. Last year they were affected by a virus that destroyed the registry and all their RAC environments were "OUT OF ORDER", the result, thousand people on vacation for a day.

They were distrustful about Linux and after came an agreement to migrate their Enterprise Manager from Windows to Linux (OMS and Repository).

How we did demonstrate how powerful and easy is RMAN to migrate databases across platforms.

• Fist of check of target platform is available from source
  

SQL> select platform_name from v$db_transportable_platform;
PLATFORM_NAME
-----------------------------------------------------------
Microsoft Windows IA (32-bit)
Linux IA (32-bit)
HP Tru64 UNIX
Linux IA (64-bit)
HP Open VMS
Microsoft Windows IA (64-bit)
Linux 64-bit for AMD
Microsoft Windows 64-bit for AMD
Solaris Operating System (x86)

• Check database object as directories that can change across platforms, also check external tables.
  

• Startup source database in read only mode

• Run the following RMAN Script

RMAN> connect target /
RMAN> convert database on target platform
convert script 'c:/temp/convert_grid.rman'
transport script 'c:/TEMP/transporta_grid.sql'
new database 'gridbd'
format 'c:/temp/gridmydb%U'
db_file_name_convert 'C:\oracle\oradata\grid','/oracle/gridbd/data2/data';
(Notice tha path change on db_file_name_convert)

• Move from source to target:
• Pfile
• New scripts
• external table files
• bfiles
• data files
  
• Check pfile, and ensure that the paths are OK

• Create temporary control file to connect rman
  

• Execute the RMAN script

RMAN> connect target /
RMAN> @/home/oracle/pboixeda/win2lnx.rman

• Shutdown the instance and remove temporary control files

• Recreate controlfile/s, take care about the used paths.

• Execute the transport script, transporta_grid.sql

• Due we were moving from a 32-bit architecture to a 64-bit architecture, there is bug reported in 386990.1 note, we had to recreate OLAP , check the note for more details.
  

• Alter or Recreate all necessary objects
  

• Launch utlrp

After this experience with Linux they are on the way to migrate all their RAC from 10gR2 on Windows to 11gR2 Linux 64 bit.

Hope it helps