Unfortunately they do not recommend how you should do this, especially when you have a FRA configured in ASM.
With the release of version 11 ASM Oracle introduced the ASMCMD cp command. I thought that solves the problem since the white paper (Oracle Database 11G Automatic Storage Management New Features Overview – published June 2007) states “The ASMCMD cp command allows you to copy files between ASM disk groups between 2 ASM servers”, but I could not get the command to copy my RMAN backupsets between ASM disk groups. I eventually logged SR 7173090.993 but even Oracle support was not sure and they wasted 2 days trying to make it work. Only after 2 days, did Oracle support say that the command does not work for copying backupsets between ASM disk groups (only data files).
OK what now?
I had a look around and decided that my only option is the cumbersome (but at least workable) DBMS_FILE_TRANSFER package.
First step is to locate the rman backupsets on the source server:
ASMCMD> pwd
+PCASDGF/CASOB1/BACKUPSET/2009_03_27
Now create the same directory structure on the remote server. On the standby server I first created an ASM Diskgroup with the same name as the FRA on production (+PCASDGF).
ASMCMD> mkdir +PCASDGF/CASOB1
ASMCMD> mkdir +PCASDGF/CASOB1/BACKUPSET
ASMCMD> mkdir +PCASDGF/CASOB1/BACKUPSET/2009_03_27
Use DBMS_FILE_TRANSFER to instantiate an ASM DataGuard database
DBMS_FILE_TRANSFER.GET_FILE contacts a remote database to read a remote file and then creates a copy of the file in the local file system. But before I can use this method I need a "stage" instance on the standby server. (I used DBCA to create a stage database - it took 20 minutes to create)
Prepare the newly created stage database to use DBMS_FILE_TRANSFER:
CONNECT sys/XXX
CREATE OR REPLACE DIRECTORY DEST_DIR AS '+PCASDGF/CASOB1/BACKUPSET/2009_03_27'
CREATE DATABASE LINK SOURCE_DB CONNECT TO system IDENTIFIED BY XXX USING 'CASOB1.VODACOM.CO.ZA';
On Primary:
CREATE OR REPLACE DIRECTORY SOURCE_DIR AS '+PCASDGF/CASOB1/BACKUPSET/2009_03_27';
Get a list of the backupsets on the source server:
ASMCMD> pwd
+PCASDGF/CASOB1/BACKUPSET/2009_03_27
ASMCMD> ls
annnf0_TAG20090327T115944_0.417.682603193
annnf0_TAG20090327T115944_0.418.682603193
...
Use an editor to create a SQL command (one per backupset) which looks like this:
execute dbms_file_transfer.get_file(source_directory_object => 'SOURCE_DIR',source_file_name => 'ncsdf0_TAG20090406T092911_0.1
367.683458159', destination_directory_object => 'DEST_DIR',destination_file_name => 'BACKUP1',source_database => 'SOURCE_DB');
execute dbms_file_transfer.get_file(source_directory_object => 'SOURCE_DIR',source_file_name => 'nnndf0_TAG20090406T092911_0.1
364.683458159', destination_directory_object => 'DEST_DIR',destination_file_name => 'BACKUP2',source_database => 'SOURCE_DB');
…
Note that the destination_file_name is not the same as the source file name. You will get an ORA-15046 if they are the same, this error is the result of the backupset being an Oracle-Managed file name.
So I execute these commands on the standby server from the stage instance. The progress of the command can be monitored using the V$SESSION_LONGOPS view. Once all the backupsets are copied over I was done with the stage database.
The next step is to create aliases for the new names of the backuppieces, so back on the source server issue:
ALTER DISKGROUP PCASDGF ADD ALIAS '+PCASDGF/CASOB1/BACKUPSET/2009_03_27/BACKUP1' for '+PCASDGF/CASOB1/BACKUPSET/2009_03_27/annnf0_TAG20090327T115944_0.417.682603193';
…
Once done, I can query V$ASM_ALIAS and there are two entries per backuppiece. One for the backuppiece and one for the alias.
The aim of doing this was to create a Data Guard instance, so before I can restore the backup I first have to prepare a Data Guard instance:
Log onto the standby server
# $export ORACLE_SID=casobc
# $orapwd=orapwcasobc password=XXX
sqlplus
SYS@casobc>create spfile from pfile; (I previously created a pfile from production with a few changes necessary for DG)
File created.
SYS@casobc>startup force nomount;
ORACLE instance started.
OK now I am ready to start the restore. First catalog the backuppieces in the source server/primary RMAN
Connect to RMAN on the primary server
RMAN> connect target sys/XXX@casob1.vodacom.co.za;
connected to target database: CASOB1 (DBID=1215042422)
RMAN> connect auxiliary /
connected to auxiliary database: CASOB1 (not mounted)
RMAN> catalog backuppiece '+PCASDGF/ CASOB1/BACKUPSET/2009_03_27/BACKUP1';
RMAN> catalog backuppiece '+PCASDGF/CASOB1/BACKUPSET/2009_03_27/BACKUP2';
…
Once done, I could list the backup in RMAN and see two entries, one for the backuppiece and one for the alias.
Eventually I am ready to use the RMAN backup to create a data guard instance.
RMAN> duplicate target database for standby ;
...
RMAN> exit
