RMAN Duplicating Databases

Duplicating Databases
=====================

This chapter contains the following topics:

Specifying Alternative Names for Duplicate Database Files

Making Disk Backups Accessible Without Shared Disk

    Specifying Alternative Names for Duplicate Database Files
    If     the source database and duplicate database do not use the same names for database files, 
    then 
        we must choose an alternative naming strategy for the duplicate files.
    end

Depending on whether the source and duplicate databases use Oracle Managed Files (OMF) or Oracle Automatic Storage Management (ASM), use one of the following strategies:

Specifying Non-OMF or Non-ASM Alternative Names for Duplicate Database Files
============================================================================

Using the CONFIGURE AUXNAME Command to Name File System Data Files and OMF or ASM Target Data Files

If     the source data files use OMF, 
then 
    we cannot rename them by using the DB_FILE_NAME_CONVERT initialization parameter. 
end

Using Non-ASM Storage discusses the details and options of OMF-managed data files.
=================================================================================

Specifying Non-OMF or Non-ASM Alternative Names for Duplicate Database Files
============================================================================

When the source and duplicate database either use different directory structures or use the same structure but we want to name the duplicate files differently, then we must specify how duplicate database files must be named.

Substitution Variables for the SET NEWNAME Command

Variable    Description
===================================================================
%b        Specifies the file name stripped of directory paths. 
        if a data file is named /oradata/prod/financial.dbf, 
        then 
            %b results in financial.dbf.
        end
===================================================================
%f        Specifies the absolute file number of the data file 
        for which the new name is generated. 
        if data file 2 is duplicated, 
        then 
            %f generates the value 2.
        end
===================================================================
%I        Specifies the DBID.
===================================================================
%N        Specifies the tablespace name.
===================================================================
%U        Specifies the following format: data-D-%d_id-%I_TS-%N_FNO-%f
===================================================================

Use one of the following techniques to provide alternate names for non-OMF or non-ASM duplicate database files:

Using the SET NEWNAME Command to Name File System Data Files and Temp Files
Using the CONFIGURE AUXNAME Command to Name File System Data Files and OMF or ASM Target Data Files
Using the SET NEWNAME Command to Name File System Data Files and Temp Files

Use the SET NEWNAME command before we execute the DUPLICATE command to name duplicate data files.

RMAN supports the following commands, listed in order of precedence:
    SET NEWNAME FOR DATAFILE and 
    SET NEWNAME FOR TEMPFILE
    SET NEWNAME FOR TABLESPACE
    SET NEWNAME FOR DATABASE

The order of precedence means that the SET NEWNAME FOR TABLESPACE command specifies names for files that are not named by the SET NEWNAME FOR DATAFILE and SET NEWNAME FOR TEMPFILE commands, whereas the SET NEWNAME FOR DATABASE command specifies names for files that are not named by the SET NEWNAME FOR TABLESPACE, SET NEWNAME FOR DATAFILE, or SET NEWNAME FOR TEMPFILE commands.

When yo use the SET NEWNAME FOR DATAFILE command, we can specify a full path as a literal, as in /oradata1/system01.dbf. However, when we use the SET command with the FOR DATABASE or FOR TABLESPACE options, we must use at least one of these substitution variables, described in Table 26-1: %b, %f, %U(%I and %N are optional).

To use the SET NEWNAME command to specify new file names:

01. Ensure that the prerequisites for the selected duplication technique are met.
02. Complete the required planning tasks before we begin database duplication.
03. Prepare the auxiliary instance that is used when we create the duplicate database.
    While duplicating an Oracle Real Application Clusters (Oracle RAC) database, 
    set the CLUSTER_DATABASE initialization parameter on the auxiliary database to FALSE. 
    This parameter can be reset to TRUE after the duplication process completes.
04. Start RMAN and connect to required databases.
05. Depending on the duplication technique preferred, 
    we may need to connect to one or more of the following: 
    target database, 
    auxiliary instance, or 
    recovery catalog.
06. Place the source database in a proper state, if necessary.
07. Optionally Configure RMAN channels to improve duplication performance. 
    Channels perform the primary task of duplicating the database.

Within a RUN command, issue the SET NEWNAME command before we issue the DUPLICATE command.

Assume the following:

DBID is 123456789
Database name is PROD
Use the following command to duplicate the database:

RUN
{
SET NEWNAME FOR DATAFILE 1 TO '/oradata1/system01.dbf'; 
SET NEWNAME FOR DATAFILE 2 TO '/oradata2/sysaux01.dbf';
SET NEWNAME FOR DATAFILE 3 TO '/oradata3/undotbs01.dbf';
SET NEWNAME FOR DATAFILE 4 TO '/oradata4/users01.dbf'; 
SET NEWNAME FOR DATAFILE 5 TO '/oradata5/users02.dbf';
SET NEWNAME FOR TEMPFILE 1 TO '/oradatat/temp01.dbf'; 
DUPLICATE TARGET DATABASE TO dupdb
  SKIP TABLESPACE tools
  LOGFILE
     GROUP 1 ('/duplogs/redo01a.log','/duplogs/redo01b.log') SIZE 4M REUSE, 
     GROUP 2 ('/duplogs/redo02a.log', '/duplogs/redo02b.log') SIZE 4M REUSE;
}

Duplicating Databases with the SET NEWNAME FOR DATAFILE and SET NEWNAME FOR TABLESPACE Commands

This example uses a single SET NEWNAME command to name all data files in the tablespace users. 
After the example completes, the file names for tablespace users are set to: /oradata4/users01.dbf and /oradata5/users02.dbf.

Use the following command to duplicate the database:

RUN
{
SET NEWNAME FOR TABLESPACE users TO '/oradata%f/%b';
SET NEWNAME FOR DATAFILE 1 TO '/oradata1/system01.dbf';
SET NEWNAME FOR DATAFILE 2 TO '/oradata2/sysaux01.dbf';
SET NEWNAME FOR DATAFILE 3 TO '/oradata3/undotbs01.dbf';
SET NEWNAME FOR TEMPFILE 1 TO '/oradatat/temp01.dbf';
DUPLICATE TARGET DATABASE TO dupdb
SKIP TABLESPACE tools
LOGFILE
   GROUP 1 ('/duplogs/redo01a.log','/duplogs/redo01b.log') SIZE 4M REUSE,
   GROUP 2 ('/duplogs/redo02a.log','/duplogs/redo02b.log') SIZE 4M REUSE;
}

Duplicating Database with the SET NEWNAME FOR DATABASE Command

This example uses a single SET command to name all data files in the database.
Use the following command to duplicate the database:

RUN
{
SET NEWNAME FOR DATABASE TO '/oradata/%U';
DUPLICATE TARGET DATABASE TO dupdb
  SKIP TABLESPACE tools
  LOGFILE
    GROUP 1 ('/duplogs/redo01a.log','/duplogs/redo01b.log') SIZE 4M REUSE,
    GROUP 2 ('/duplogs/redo02a.log','/duplogs/redo02b.log') SIZE 4M REUSE;
}
The following table shows the results from this example.

Results for the SET NEWNAME DATABASE Command

Before 
SET NEWNAME 
DATABASE        Tablespace Name    Data File Number    After SET NEWNAME DATABASE TO '/oradata/%U';
.../system01.dbf     SYSTEM            1            /oradata/data-D-PROD_id-87650928_TS-SYSTEM_FNO-1
.../sysaux01.dbf    SYSAUX        2            /oradata/data-D-PROD_id-87650928_TS-SYSAUX_FNO-2
.../undotbs01.dbf    UNDOTS        3            /oradata/data-D-PROD_id-87650928_TS-UNDOTS_FNO-3
.../users01.dbf        USERS        4            /oradata/data-D-PROD_id-87650928_TS-USERS_FNO-4
.../users02.dbf        USERS        5            /oradata/data-D-PROD_id-87650928_TS-USERS_FNO-5
.../temp01.dbf        TEMP        1            /oradata/data-D-PROD_id-87650928_TS-TEMP_FNO-1

Using the CONFIGURE AUXNAME Command to Name File System Data Files and OMF or ASM Target Data Files
===================================================================================================
The CONFIGURE AUXNAME command is an alternative to the SET NEWNAME command. The difference is that after we configure the auxiliary name the first time, additional DUPLICATE commands reuse the configured settings. In contrast, we must reissue the SET NEWNAME command every time we execute the DUPLICATE command.

To use the CONFIGURE AUXNAME command to specify names for duplicate data files:

Issue a CONFIGURE AUXNAME command for each file to name in the duplicate database.

For example, enter the following commands at the RMAN prompt to specify names for files data files 1 through 5:

CONFIGURE AUXNAME FOR DATAFILE 1 TO '/oradata1/system01.dbf';
CONFIGURE AUXNAME FOR DATAFILE 2 TO '/oradata2/sysaux01.dbf';
CONFIGURE AUXNAME FOR DATAFILE 3 TO '/oradata3/undotbs01.dbf';
CONFIGURE AUXNAME FOR DATAFILE 4 TO '/oradata4/users01.dbf'; 
CONFIGURE AUXNAME FOR DATAFILE 5 TO '/oradata5/users02.dbf';

Issue a DUPLICATE command.

For example, enter the following command at the RMAN prompt:

SET NEWNAME FOR TEMPFILE 1 TO '/oradatat/temp01.dbf'; 
DUPLICATE TARGET DATABASE
  TO dupdb
  SKIP TABLESPACE tools
  LOGFILE
     GROUP 1 ('/duplogs/redo01a.log','/duplogs/redo01b.log') SIZE 4M REUSE,
     GROUP 2 ('/duplogs/redo02a.log','/duplogs/redo02b.log') SIZE 4M REUSE;


Specifying OMF or ASM Alternative Names for Duplicate Database Files

we must specify how to name duplicate database files when the source database and duplicate database do not use the same names for database files.

The following sections discuss requirements and procedures for creating a duplicate database when some or all files of the duplicate database use OMF or ASM:

Settings and Restrictions for OMF Initialization Parameters
Setting Initialization Parameters for ASM

Examples: Duplicating Databases to ASM
======================================

Using the SET NEWNAME Command to Create OMF or ASM Files
Using the DB_FILE_NAME_CONVERT Parameter to Generate Names for Non-OMF or ASM Data Files
Using the LOG_FILE_NAME_CONVERT Parameter to Generate Names for Non-OMF or ASM Log Files

Settings and Restrictions for OMF Initialization Parameters
============================================================

When we create a duplicate database that uses OMF, we must set initialization parameters in the auxiliary instance. If we use the SPFILE option of the DUPLICATE command to name the files, then we can set initialization parameters in the SPFILE option.

Initialization Parameters for Oracle Managed Files

Initialization Parameter    Purpose    Recommendation
DB_CREATE_FILE_DEST        Specifies the default location for Oracle managed data files. This location is also the default                 location for Oracle managed control files and online logs if no DB_CREATE_ONLINE_LOG_DEST                     initialization parameters are specified.

                Set this parameter to the location for OMF. Any database files that have no location specified                     are created in the directory specified by the DB_CREATE_FILE_DEST parameter. we can override                     the default for specific files by using the SET NEWNAME command, as described in "Using the SET                 NEWNAME Command to Create OMF or ASM Files".

DB_CREATE_ONLINE_LOG_DEST_n    Specifies the default location for Oracle managed control files and online redo logs. If                     multiple parameters are set, then one control file and one online redo log is created in each                     location.

                Set these parameters (_1, _2, and so on) only if we want to multiplex the control files and                     online redo log files in multiple locations.

DB_RECOVERY_FILE_DEST        Specifies the default location for the fast recovery area. The fast recovery area contains                     multiplexed copies of current control files and online redo log files.

Set this parameter if we want a multiplexed copy of the control file and online redo log file in the recovery area.
------------------------------------------------------------------------------------------------------------------
Initialization Parameter Restrictions for Oracle Managed Files

Initialization Parameter    Purpose    Restriction
CONTROL_FILES            Specifies one or more names of control files, separated by commas.

                Do not set this parameter if we want the duplicate database control files in an OMF format.                     When we use control files in an OMF format, Oracle recommends that we use a server parameter                     file at the duplicate database .

DB_FILE_NAME_CONVERT        Converts the file name of a new data file on the primary database to a file name on the                     duplicate database.

                Do not set this parameter. Omitting this parameter enables the database to generate valid                     Oracle managed file names for the duplicate data files.

LOG_FILE_NAME_CONVERT        Converts the file name of a new log file on the primary database to the file name of a log file                 on the standby database.

                Do not set this parameter. Omitting this parameter allows the database to generate valid Oracle                 managed online redo log file names.

                To direct duplicate database online redo log files to Oracle managed storage, we can use the                     DB_CREATE_FILE_DEST, DB_RECOVERY_FILE_DEST, or DB_CREATE_ONLINE_LOG_DEST_n initialization                     parameters to identify an Oracle managed location for the online logs.

Setting Initialization Parameters for ASM
=========================================
We must identify the initialization parameters that control the location where files are created and set these parameters to an ASM disk group.

The procedure for creating a duplicate database to an ASM location is similar to that of creating a duplicate database to OMF. For example, set the 
DB_CREATE_FILE_DEST, 
DB_CREATE_ONLINE_DEST_n, and 
CONTROL_FILES parameters to +DISK1.

Duplicating a Database from a File System to ASM
=================================================

In this example, we use active database duplication. If the source database uses a server parameter file (or a backup is available), then we can create a temporary initialization parameter file on the destination host and set only the DB_NAME parameter.

Assume that the source database prod is on host1 and stores its data files in a non-ASM file system. The control files for prod are located in /oracle/oradata/prod/. we want to duplicate the source database to database dupdb on remote host host2. we want to store the duplicate database files in ASM disk group +DISK1.

After connecting RMAN to the target, duplicate, and recovery catalog databases, run the following RMAN script to duplicate the database.

DUPLICATE TARGET DATABASE TO dupdb
FROM ACTIVE DATABASE
SPFILE
PARAMETER_VALUE_CONVERT '/oracle/oradata/prod/', '+DISK1'
SET DB_CREATE_FILE_DEST +DISK1;

When the DUPLICATE command completes, the duplicate database is created, with data files, online redo log files, and control files in ASM disk group +DISK1.


Duplicating a Database from ASM to ASM
======================================

In this example, we use active database duplication. 

If the source database uses a server parameter file (or a backup is available), 
then 
    we can create a temporary initialization parameter file on the destination host and set only the DB_NAME parameter.
end

Assume that the source database prod is on host1 and stores its data files in ASM disk group +DISK1. 
We want to duplicate the target to database dupdb on remote host host2. 
We want to store the data files for dupdb in ASM. 
Specifically, We want to store the data files and control files in disk group +DISK2.

In the DUPLICATE command, set PARAMETER_VALUE_CONVERT to convert all directory locations from +DISK1 to +DISK2. The new file names in +DISK2 are generated by ASM and do not match the original file names in disk group +DISK1.

After connecting to the target, duplicate, and catalog databases, run the following RMAN script to duplicate the database.

DUPLICATE TARGET DATABASE TO dupdb
FROM ACTIVE DATABASE
SPFILE PARAMETER_VALUE_CONVERT '+DISK1','+DISK2'
SET DB_RECOVERY_FILE_DEST_SIZE='750G';

When the DUPLICATE command completes, the duplicate database is created, with data files, online redo logs, and control files in the larger ASM disk group +DISK2.

Using the SET NEWNAME Command to Create OMF or ASM Files
--------------------------------------------------------

To name Oracle managed data files, we can use the SET NEWNAME command with the TO NEW option instead of the TO 'filename' option. RMAN creates the specified data files or temp files with OMF names in the location specified by the DB_CREATE_FILE_DEST parameter.

To use the SET NEWNAME command to specify names for OMF:

Set the DB_CREATE_FILE_DEST initialization parameter at the auxiliary instance to the desired location.
Enclose the DUPLICATE command in a RUN block and use the SET NEWNAME command with the TO NEW option for OMF.
Duplicating Databases with the SET NEWNAME FOR DATAFILE and SET NEWNAME FOR TABLESPACE Commands

This example illustrates a script that specifies literal names for data files 1 thru 5. The only Oracle Managed Files in the source database are the data files in the users tablespace. Therefore, the TO NEW option is specified in the SET NEWNAME command for these files.

RUN
{
SET NEWNAME FOR TABLESPACE users TO NEW;
SET NEWNAME FOR DATAFILE 3 TO NEW;
SET NEWNAME FOR DATAFILE 1 TO '/oradata1/system01.dbf';
SET NEWNAME FOR DATAFILE 2 TO '/oradata2/sysaux01.dbf';
SET NEWNAME FOR TEMPFILE 1 TO '/oradatat/temp01';
DUPLICATE TARGET DATABASE TO dupdb
SKIP TABLESPACE tools
LOGFILE
    GROUP 1 ('/duplogs/redo01a.log','/duplogs/redo01b.log') SIZE 4M REUSE,
    GROUP 2 ('/duplogs/redo02a.log','/duplogs/redo02b.log') SIZE 4M REUSE;
}

Using the SET NEWNAME Command to Create Files in an ASM Disk Group
This example uses the SET NEWNAME command to direct individual data files, temp files, or tablespaces to a specified ASM disk group.

RUN
{
SET NEWNAME FOR DATAFILE 1 TO "+DGROUP1";
SET NEWNAME FOR DATAFILE 2 TO "+DGROUP2";
.
.
.
DUPLICATE TARGET DATABASE
TO dupdb
FROM ACTIVE DATABASE
SPFILE SET DB_CREATE_FILE_DEST +DGROUP3;
}

Using the DB_FILE_NAME_CONVERT Parameter to Generate Names for Non-OMF or ASM Data Files

In addition to using the SET NEWNAME or CONFIGURE AUXNAME commands, we can use the DB_FILE_NAME_CONVERT parameter to transform target file names. we can either specify the DB_FILE_NAME_CONVERT option in the DUPLICATE command or we can set it in the initialization parameter file of the auxiliary instance.

For example, we can change the target file name from the /oracle/ directory to the /dup/oracle/ directory. The DB_FILE_NAME_CONVERT parameter allows we to specify multiple conversion file name pairs. It can also be used to produce names for data files and temp files.

Restrictions of the DB_FILE_NAME_CONVERT Parameter
--------------------------------------------------

we cannot use the DB_FILE_NAME_CONVERT option of the DUPLICATE command to control generation of new names for files at the duplicate instance that are in the OMF format at the source database instance.

Using the LOG_FILE_NAME_CONVERT Parameter to Generate Names for Non-OMF or ASM Log Files

If     the LOG_FILE clause has been omitted and none of the OMF initialization parameters 
    DB_CREATE_FILE_DEST,         
    DB_CREATE_ONLINE_DEST_n, or 
    DB_RECOVERY_FILE_DEST are specified, 
then     the LOG_FILE_NAME_CONVERT parameter can transform target file names. This works in the same way that the         DB_FILE_NAME_CONVERT parameter does to transform target file names from log_* to duplog_*.
end

We can specify multiple conversion file name pairs with this parameter. When we specify the LOG_FILE_NAME_CONVERT parameter, RMAN uses the REUSE parameter when creating the online redo logs. If an online redo log file exists at the named location and is of the correct size, then it is reused for the duplication process.

Restrictions of the LOG_FILE_NAME_CONVERT Parameter
----------------------------------------------------

01. If OMF initialization parameters are set then do not specify the LOG_FILE_NAME_CONVERT parameter.
02. The LOG_FILE_NAME_CONVERT parameter cannot be specified as a clause in the DUPLICATE command, it can only be specified in the initialization parameter of the auxiliary instance.
03. We cannot use the LOG_FILE_NAME_CONVERT initialization parameter to control generation of new names for files at the duplicate instance that are in the OMF format at the source database instance.

Making Disk Backups Accessible Without Shared Disk
==================================================

We can use the shared disk technique to make backups available to the auxiliary instance. 
When NFS or shared disk is not an option, then the path that stores the backups must exist on both the source and destination hosts, unless the BACKUP LOCATION option is used for the DUPLICATE command without a target or recovery catalog connection.

Assume that we maintain two hosts, srchost and dsthost. The database on srchost is srcdb. The RMAN backups of srcdb reside in the /dsk1/bkp directory on host srchost. The directory /dsk1/bkp is in use on the destination host, so we intend to store backups in the /dsk2/dup directory on the destination host.

To transfer the backups from the source host to the destination host:
=====================================================================

Create a directory in the source host that has the same name as the directory on the destination host that contains the backups.

For example, if we intend to store the RMAN backups in the /dsk2/dup directory on the destination host, then create the /dsk2/dup directory on the source host.

On the source host, copy the backups to the directory created in the previous step, and then catalog the backups. 

We can use either of the following approaches:

Connect RMAN to the source database as TARGET and use the BACKUP command to back up the backups. 
For example, use the BACKUP COPY OF DATABASE command to copy the backups in /dsk1/bkp on the source host to /dsk2/dup on the source host. In this case, RMAN "automatically catalogs" the backups in the new location. 

If     we are duplicating a PDB, 
then     
    use the PLUGGABLE DATABASE syntax of the BACKUP COPY OF command to copy only the backups of the PDB.
end

Use an operating system utility to copy the backups in the /dsk1/bkp directory on the source host to the /dsk2/dup directory on the source host. Afterward, connect RMAN to the source database as TARGET and use the "CATALOG" command to update the source control file with the location of the manually transferred backups.

Manually transfer the backups in the new directory on the source host to the identically named directory on the destination host.

For example, use FTP to transfer the backups in the /dsk2/dup directory on the source host to the /dsk2/dup directory on the destination host.

The auxiliary channel can search for backups in the /dsk2/dup directory on the destination host and restore them.

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