Rename or move ASM datafile to different Diskgroup

Aim: To move datafile 4 to +USER_DATA asm diskgroup:


SQL> select file_id,file_name from dba_data_files;

   FILE_ID FILE_NAME
---------- -------------------------------------------
4 +DATA/racdb/datafile/users.259.866896399
3 +DATA/racdb/datafile/undotbs1.258.866896399
2 +DATA/racdb/datafile/sysaux.257.866896399
1 +DATA/racdb/datafile/system.256.866896397
5 +DATA/racdb/datafile/undotbs2.264.866897005

SQL> select name,free_mb,group_number from v$asm_diskgroup ;

NAME  FREE_MB GROUP_NUMBER
------------------------------ ---------- ------------
DATA      225     1
USER_DATA     4101     2
FRA         3999     3

SQL> ALTER DATABASE DATAFILE '+DATA/racdb/datafile/users.259.866896399' OFFLINE ;

Database altered.

RMAN> COPY DATAFILE '+DATA/racdb/datafile/users.259.866896399' TO '+USER_DATA' ;

Starting backup at 23-DEC-14
using target database control file instead of recovery catalog
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=57 instance=racdb1 device type=DISK
channel ORA_DISK_1: starting datafile copy
input datafile file number=00004 name=+DATA/racdb/datafile/users.259.866896399
output file name=+USER_DATA/racdb/datafile/users.256.867064887 tag=TAG20141223T112114 RECID=1 STAMP=867064896
channel ORA_DISK_1: datafile copy complete, elapsed time: 00:00:26
Finished backup at 23-DEC-14

SQL> ALTER DATABASE RENAME FILE '+DATA/racdb/datafile/users.259.866896399' TO '+USER_DATA/racdb/datafile/users.256.867064887' ;

Database altered.

SQL> RECOVER DATAFILE '+USER_DATA/racdb/datafile/users.256.867064887' ;

Media recovery complete.

SQL> ALTER DATABASE DATAFILE '+USER_DATA/racdb/datafile/users.256.867064887' online ;

Database altered.

 FILE_ID FILE_NAME STATUS
---------- ---------------------------------------------------------------------------------------------------------------
4    +USER_DATA/racdb/datafile/users.256.867064887 AVAILABLE
3 +DATA/racdb/datafile/undotbs1.258.866896399         AVAILABLE
2 +DATA/racdb/datafile/sysaux.257.866896399           AVAILABLE
1 +DATA/racdb/datafile/system.256.866896397 AVAILABLE
5 +DATA/racdb/datafile/undotbs2.264.866897005         AVAILABLE

Note:

 The steps provided above assume that the database is open and in Archivelog mode.
Besides these steps are not appropriated for system or sysaux datafiles. For System and Sysaux an approach similar to the one given below can be used
as per oracle support metalink :

1. Create a Copy of datafile in target Diskgroup:
RMAN> backup as copy tablespace system format '<New DG>';
RMAN> backup as copy tablespace sysaux format '<New DG>';
2. Then shutdown the database and restart to a mounted state
RMAN> shutdown immediate;
RMAN> startup mount;
3. switch the datafiles to the copy
RMAN> switch tablespace system to copy;
RMAN> switch tablespace sysaux to copy;
4. Recover the changes made to these tablespaces;
RMAN> recover database;

Also
make sure you run RMAN crosscheck copy and delete expired copy to update the controlfile and catalog for
your backups to run without issues.