CLONE ORACLE DATABASE WITH COLD BACKUP:

1. Identify and copy the database files
With the source database started, identify all of the database’s files. The following query will display all datafiles, tempfiles and redo logs:

set lines 100 pages 999
col name format a50
select name, bytes
from (select name, bytes
from v$datafile
union all
select name, bytes
from v$tempfile
union all
select lf.member “name”, l.bytes
from v$logfile lf
, v$log l
where lf.group# = l.group#) used
, (select sum(bytes) as poo
from dba_free_space) free
/

OR

SQL>Select name from v$datafile;
SQL>Select member from v$logfile;

Make sure that the clone databases file-system is large enough and has all necessary directories.
If the source database has a complex file structure, you might want to consider modifying the
above sql to produce a file copy script.

Stop the source database with:

shutdown immediate

Copy, scp or ftp the files from the source database/machine to the target.
Do not copy the control files across. Make sure that the files have the correct permissions and ownership.

Start the source database up again

startup

2. Produce a pfile for the new database

This step assumes that you are using a spfile. If you are not, just copy the existing pfile.

From sqlplus:

create pfile=’init.ora’ from spfile;
This will create a new pfile in the $ORACLE_HOME/dbs directory.

Once created, the new pfile will need to be edited. If the cloned database is to have a new name,
this will need to be changed, as will any paths. Review the contents of the file and make
alterations as necessary.
Also think about adjusting memory parameters. If you are cloning a production database onto
a slower development machine you might want to consider reducing some values.

Now open the parameter file in clone database and change the following parameters with the respective current location.

CONTROL FILES
BACKGROUND_DUMP_DEST
USER_DUMP_DEST
CORE_DUMP_DEST
LOG_ARCHIVE_DEST_1

And Place the BST4 pfile on /$ORACLE_HOME/dbs

Note. Pay particular attention to the control locations.

3. Create the clone controlfile

Create a control file for the new database. To do this, connect to the source database and request a dump of the current control file. From sqlplus:

alter database backup controlfile to trace as ‘/home/oracle/cr_.sql’
/

4. Edit the file

FROM: CREATE CONTROLFILE REUSE DATABASE “BST2” RESETLOGS …
TO: CREATE CONTROLFILE set DATABASE “BST4” RESETLOGS …

Change the word ‘REUSE’ to ‘set’ and the ‘BST2’ to ‘BST4’. Also change the datafiles location parameter to BST4 database location.

CONTROL FILES
BACKGROUND_DUMP_DEST
USER_DUMP_DEST
CORE_DUMP_DEST
LOG_ARCHIVE_DEST_1

And Place the BST4 pfile on /DV1_u31/oraBST2/db/tech_st/10.2.0/dbs

5. In clone database SERVER export ORACLE_SID environment variable and start the instance
$export ORACLE_SID=bst4
$sqlplus
Enter User:/ as sysdba
SQL> startup nomount pfile=’initBST4.ora’;

6. Run create controlfile script to create the controlfile
SQL>@createcontrolfile.sql

Trouble shoot:

It is quite common to run into problems at this stage. Here are a couple of common errors and solutions:

ORA-01113: file 1 needs media recoveryYou probably forgot to stop the source database before copying the files.
Go back to step 1 and recopy the files.

ORA-01503: CREATE CONTROLFILE failed
ORA-00200: controlfile could not be created
ORA-00202: controlfile: ‘/u03/oradata/dg9a/control01.ctl’
ORA-27038: skgfrcre: file exists
Double check the pfile created in step 2. Make sure the control_files setting
is pointing at the correct location. If the control_file setting is ok, make sure that the control
files were not copied with the rest of the database files. If they were, delete or rename them.

7. Open the database

SQL>alter database open;

8. Perform a few checks

If the last step went smoothly, the database should be open.
It is advisable to perform a few checks at this point:

Check that the database has opened with:
select status from v$instance;
The status should be ‘OPEN’

Make sure that the datafiles are all ok:
select distinct status from v$datafile;
It should return only ONLINE and SYSTEM.

Take a quick look at the alert log too.

9. Set the databases global name

The new database will still have the source databases global name. Run the following to reset it:

alter database rename global_name to
/

10. Create a spfile

From sqlplus:
create spfile from pfile;

11. Change the database ID

If RMAN is going to be used to back-up the database, the database ID must be changed.
If RMAN isn’t going to be used, there is no harm in changing the ID anyway – and it’s a good practice to do so.

From sqlplus:

shutdown immediate
startup mount
exit
From unix:

nid target=/
NID will ask if you want to change the ID. Respond with ‘Y’. Once it has finished, start the database up again in sqlplus:

shutdown immediate
startup mount
alter database open resetlogs
/
12. Configure TNS

Add entries for new database in the listener.ora and tnsnames.ora as necessary.

13. Finished
That’s it!

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About shanojkumar

* Has 12 years of experience in Planning, Implementing, Managing and Monitoring the Oracle Databases as an (Oracle 10g & 11g OCP) Certified Oracle Database Administrator.
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