Move a datafile with RMAN

Using RMAN is the best way before 12c to relocate a datafile with a minimum downtime. The only downtime is for switching from the old datafile to the new one and recover it. That means that the datafile size as no impact on the downtime.

Check schmea report before moving datafile.

Here is the situation before moving the datafile

RMAN> report schema
2> ;

using target database control file instead of recovery catalog
Report of database schema for database with db_unique_name XE

List of Permanent Datafiles
===========================
File Size(MB) Tablespace RB segs Datafile Name
---- -------- -------------------- ------- ------------------------
1 360 SYSTEM *** C:\ORACLEXE\APP\ORACLE\ORADATA\XE\SYSTEM.DBF
2 650 SYSAUX *** C:\ORACLEXE\APP\ORACLE\ORADATA\XE\UNDOTBS1.DBF
3 25 UNDOTBS1 *** C:\ORACLEXE\APP\ORACLE\ORADATA\XE\SYSAUX.DBF
4 100 USERS *** C:\ORACLEXE\APP\ORACLE\ORADATA\XE\USERS.DBF


List of Temporary Files
=======================
File Size(MB) Tablespace Maxsize(MB) Tempfile Name
---- -------- -------------------- ----------- --------------------
1 20 TEMP 32767 C:\ORACLEXE\APP\ORACLE\ORADATA\XE\TEMP.DBF


1.Create a copy of datafile to new destination.

The first step is to create a copy of your datafile in the new destination. Here, we will copy the USERS datafile to
C:\ORACLEXE\APP\ORACLE\ORADATA2\XE:


RMAN> copy datafile 4 to 'C:\ORACLEXE\APP\ORACLE\ORADATA2\XE\USERS.DBF';

Starting backup at 14-01-27
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=50 device type=DISK
channel ORA_DISK_1: starting datafile copy
input datafile file number=00004 name=C:\ORACLEXE\APP\ORACLE\ORADATA\XE\USERS.DBF
output file name=C:\ORACLEXE\APP\ORACLE\ORADATA2\XE\USERS.DBF tag=TAG20140127T132133 RECID=1 STAMP=837955296
channel ORA_DISK_1: datafile copy complete, elapsed time: 00:00:07
Finished backup at 14-01-27

2.Take tablespace offline.

Now I hae a copy of my datafile in the new destination, I have to switch from the old datafile to the new one. Of course this operation cannot be done online, I’ll have to put my tablespace offline, this is the begining of the downtime.

RMAN> SQL 'ALTER TABLESPACE USERS OFFLINE';

sql statement: ALTER TABLESPACE USERS OFFLINE

3.Switch old datafile to new datafile.

Now I can switch from the old datafile to the new one:

RMAN> SWITCH DATAFILE 4 TO COPY;

datafile 4 switched to datafile copy "C:\ORACLEXE\APP\ORACLE\ORADATA2\XE\USERS.DBF"

4.Recover the datafile.

Now we have to recover the datafile:

RMAN> RECOVER DATAFILE 4;

Starting recover at 14-01-27
using channel ORA_DISK_1

starting media recovery
media recovery complete, elapsed time: 00:00:01

Finished recover at 14-01-27

5.Put tablespace back to online.

And we put back the tablespace USERS online:

RMAN> SQL 'ALTER TABLESPACE USERS ONLINE';

sql statement: ALTER TABLESPACE USERS ONLINE

6. Check status now.

Here is the new situation:

Report of database schema for database with db_unique_name XE

RMAN> report schema

List of Permanent Datafiles
===========================
File Size(MB) Tablespace RB segs Datafile Name
---- -------- -------------------- ------- ------------------------
1 360 SYSTEM *** C:\ORACLEXE\APP\ORACLE\ORADATA\XE\SYSTEM.DBF
2 650 SYSAUX *** C:\ORACLEXE\APP\ORACLE\ORADATA\XE\UNDOTBS1.DBF
3 25 UNDOTBS1 *** C:\ORACLEXE\APP\ORACLE\ORADATA\XE\SYSAUX.DBF
4 100 USERS *** C:\ORACLEXE\APP\ORACLE\ORADATA2\XE\USERS.DBF

List of Temporary Files
=======================
File Size(MB) Tablespace Maxsize(MB) Tempfile Name
---- -------- -------------------- ----------- --------------------
1 20 TEMP 32767 C:\ORACLEXE\APP\ORACLE\ORADATA\XE\TEMP.DBF

The old datafile is kept as copy:

7.Check old datafile copy.

RMAN> list copy of datafile 4;

List of Datafile Copies
=======================

Key File S Completion Time Ckp SCN Ckp Time
------- ---- - --------------- ---------- ---------------
2 4 A 14-01-27 379024 14-01-27
Name: C:\ORACLEXE\APP\ORACLE\ORADATA\XE\USERS.DBF

Check 8.Remove old copy if do not need

We can remove it as we no longer need it:

RMAN> DELETE DATAFILECOPY 2;

released channel: ORA_DISK_1
allocated channel: ORA_DISK_1
channel ORA_DISK_1: SID=50 device type=DISK
List of Datafile Copies
=======================

Key File S Completion Time Ckp SCN Ckp Time
------- ---- - --------------- ---------- ---------------
2 4 A 14-01-27 379024 14-01-27
Name: C:\ORACLEXE\APP\ORACLE\ORADATA\XE\USERS.DBF

Do you really want to delete the above objects (enter YES or NO)? yes
deleted datafile copy
datafile copy file name=C:\ORACLEXE\APP\ORACLE\ORADATA\XE\USERS.DBF RECID=2 STAMP=837955601

Deleted 1 objects


And its done :)




I hope this article helped you. Your suggestions/feedback are most welcome.

Keep learning... Have a great day!!!