4 Starting and Interacting with the RMAN Client

Entering RMAN Commands at the RMAN Prompt

When the RMAN client is ready for your commands, it displays the command prompt, as in this example:

RMAN> 

Enter commands for RMAN to execute. For example:

RMAN> CONNECT TARGET
RMAN> BACKUP DATABASE;

Most RMAN commands take some parameters and must end with a semicolon. Some commands, such as STARTUP, SHUTDOWN, and CONNECT, can be used with or without a semicolon.

When you enter a line of text that is not a complete command, RMAN prompts for continuation input with a line number. For example:

RMAN> BACKUP DATABASE
2> INCLUDE CURRENT 
3> CONTROLFILE
4> ;

Using Command Files with RMAN

For repetitive tasks, you can create a text file containing RMAN commands, and start the RMAN client with the @ argument, followed by a file name. For example, create a text file cmdfile1 in the current directory containing one line of text as shown here:

BACKUP DATABASE PLUS ARCHIVELOG;

You can run this command file from the command line as shown in this example, and the command contained in it is executed:

% rman TARGET / @cmdfile1

After the command completes, RMAN exits.

You can also use the @ command at the RMAN command prompt to execute the contents of a command file during an RMAN session. RMAN reads the file and executes the commands in it. For example:

RMAN> @cmdfile1

After the command file contents have been executed, RMAN displays the following message:

RMAN>  **end-of-file**

Unlike the case where a command file is executed from the operating system command line, RMAN does not exit.

Entering Comments in RMAN Command Files

The comment character in RMAN is a pound sign (#). All text from the pound sign to the end of the line is ignored. For example, the following command file contents backs up the database and archived redo log files and includes comments:

# Command file name: mybackup.rman
# The following command backs up the database
BACKUP DATABASE;
# The following command backs up the archived redo logs
BACKUP ARCHIVELOG ALL;

The following example shows that you can break a single RMAN command across multiple lines:

RMAN> BACKUP # this is a comment
2> SPFILE;

Starting backup at 30-APR-07
allocated channel: ORA_DISK_1
     .
     .
     .

Using Substitution Variables in Command Files

When running a command file, you can specify one or more values in a USING clause for use in substitution variables in a command file. In this way, you can make your command files dynamic.

As in SQL*Plus, &1 indicates where to place the first value, &2 where to place the second value, and so on. The substitution variable syntax is &integer followed by an optional period, for example, &1.3. The optional period is part of the variable and replaced with the value, thus enabling the substitution text to be immediately followed by another integer. For example, if you pass the value mybackup to a command file containing the variable &1.3, then the result of the substitution is mybackup3.

The following procedure explains how to create and use a dynamic shell script that calls a command file containing substitution variables.

To create and use a dynamic shell script:

1. Create an RMAN command file that uses substitution variables.

   The following example shows the contents of a command file named quarterly_backup.cmd, which is run every quarter. The script uses substitution variables for the name of the tape set, for a string in the FORMAT specification, and for the name of the restore point to be created.

   
   # quarterly_backup.cmd
   CONNECT TARGET /
   RUN
   {
     ALLOCATE CHANNEL c1
       DEVICE TYPE sbt
       PARMS 'ENV=(OB_MEDIA_FAMILY=&1)';
     BACKUP DATABASE 
       TAG &2 
       FORMAT '/disk2/bck/&1%U.bck'
       KEEP FOREVER 
       RESTORE POINT &3;
   }
   EXIT;
   

2. Create a shell script that you can use to run the RMAN command file created in the previous step.

   The following example creates a shell script named runbackup.sh. The example creates shell variables for the format and restore point name and accepts the values for these variables as command-line arguments to the script.

   
   #!/bin/tcsh
   # name: runbackup.sh
   # usage: use the tag name and number of copies as arguments
   set media_family = $argv[1]
   set format = $argv[2]set restore_point = $argv[3]
   rman @'/disk1/scripts/whole_db.cmd' USING $media_family $format $restore_point
   

3. Execute the shell script created in the previous step, specifying the desired arguments on the command line.

   The following example runs the runbackup.sh shell script and passes it archival_backup as the media family name, bck0906 as the format string, and FY06Q3 as the restore point name.

   % runbackup.sh archival_backup bck0906 FY06Q3
   

Checking RMAN Syntax

You may want to test RMAN commands for syntactic correctness without executing them. Use the command-line argument CHECKSYNTAX to start the RMAN client in a mode in which it only parses the commands that you enter and returns an RMAN-00558 error for commands that are not legal RMAN syntax.

RMAN> CONNECT TARGET *
2> BACKUP TAG 
Enter value for 1: mybackup
abc COPIES 
Enter value for 2: mybackup
abc
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-00558: error encountered while parsing input commands
RMAN-01009: syntax error: found "identifier": expecting one of: "integer"
RMAN-01008: the bad identifier was: mybackup
RMAN-01007: at line 2 column 25 file: /tmp/whole_db.cmd

About RMAN Database Connections

To perform useful work, the RMAN client must connect to a database. The following table describes the types of database connections that you can make with RMAN.

% ORACLE_SID=prod; export ORACLE_SID

% rman TARGET /

% rman TARGET SYS@prod

target database Password: password
connected to target database: PROD1 (DBID=39525561)

Making RMAN Database Connections from the Operating System Command Line

To connect to a target database from the operating system command line, enter the rman command followed by the connection information. You can begin executing commands after the RMAN prompt is displayed.

In the examples in this chapter, the generic values have the meanings shown in Table 4-2.

Example 4-2 illustrates a connection to a target database that uses operating system authentication. The NOCATALOG option indicates that a recovery catalog is not used in the session.

% rman TARGET / NOCATALOG

connected to target database: PROD (DBID=39525561)
using target database control file instead of recovery catalog
 
RMAN>

Example 4-3 illustrates a connection to a target database that uses Oracle Net authentication. RMAN prompts for the password.

% rman TARGET SYS@prod NOCATALOG

target database Password: password
connected to target database: PROD (DBID=39525561)

RMAN>

Use the CATALOG keyword to connect to a recovery catalog. Example 4-4 illustrates a connection that uses Oracle Net authentication for the target and recovery catalog databases. In both cases RMAN prompts for a password.

% rman TARGET SYS@prod CATALOG rco@catdb

target database Password: password
connected to target database: PROD (DBID=39525561)
recovery catalog database Password: password
connected to recovery catalog database

RMAN>

You can also start RMAN without specifying NOCATALOG or CATALOG. If you do not specify NOCATALOG on the command line, and if you do not specify CONNECT CATALOG after RMAN has started, then RMAN defaults to NOCATALOG mode the first time that you run a command that requires the use of the RMAN repository.

If you connect to the target database on the operating system command line, then you can begin executing commands after the RMAN prompt is displayed.

Making Database Connections from the RMAN Prompt

If you start RMAN without connecting to a target database, then you must issue a CONNECT TARGET command at the RMAN prompt to connect to a target database and begin performing useful work.

To make a database connection from the RMAN prompt:

1. On the operating system command line, start the RMAN client without making a database connection. For example, enter rman as follows:

   % rman
   RMAN>
   

2. At the RMAN prompt, enter one or more CONNECT commands.

   The following example connects to a target database using operating system authentication:

   
   RMAN> CONNECT TARGET /
   

   The following alternative example connects to a target database and then a recovery catalog. The target connection uses operating system authentication, whereas the catalog database connection uses Oracle Net authentication. RMAN prompts for the password of the recovery catalog user.

   RMAN> CONNECT TARGET /
   RMAN> CONNECT CATALOG rco@catdb
   
   recovery catalog database Password: password
   connected to recovery catalog database
   

   The following example connects to a target database with database-level credentials. RMAN prompts for the SYS password.

   
   % rman
   RMAN> CONNECT TARGET SYS@prod
   
   target database Password: password
   connected to target database: PROD (DBID=39525561)
   

Connecting RMAN to an Auxiliary Database

To use the DUPLICATE command, you must connect to an auxiliary instance. To perform RMAN tablespace point-in-time recovery (TSPITR), you may also need to connect to an auxiliary instance.

The form of an auxiliary connection is identical to a target database connection, except that you use the AUXILIARY keyword instead of the TARGET keyword. Example 4-5 connects to a target database and auxiliary instance from the RMAN prompt.

% rman
RMAN> CONNECT TARGET /
RMAN> CONNECT AUXILIARY SYS@aux

auxiliary database Password: password
connected to auxiliary database: PROD (DBID=30472568)

Making RMAN Database Connections Within Command Files

If you create an RMAN command file which uses a CONNECT command with database level credentials (user name and password), then anyone with read access to this file can learn the password. There is no secure way to incorporate a CONNECT string with a password into a command file.

If you create an RMAN command file which uses a CONNECT command, then RMAN does not echo the connect string when you run the command file with the @ command. This behavior prevents connect strings from appearing in any log files that contain RMAN output. For example, suppose you create a command file listbkup.rman as follows:

cat > listbkup.rman << EOF
CONNECT TARGET /
LIST BACKUP;
EOF

You execute this script by running RMAN with the @ command line option as follows:

% rman @listbkup.rman

When the command file executes, RMAN replaces the connection string with an asterisk, as shown in the following output:

RMAN> CONNECT TARGET *
2> LIST BACKUP;
3>
connected to target database: RDBMS (DBID=771530996)

using target database control file instead of recovery catalog

List of Backup Sets
===================
. . .

Diagnosing RMAN Connection Problems

When diagnosing errors RMAN encounters in connecting to the target, catalog and auxiliary databases, using SQL*Plus to connect to the databases directly can reveal underlying problems with the connection information or the databases.

RMAN> CONNECT TARGET /

SQL> CONNECT / AS SYSDBA

Executing Multiple RMAN Commands in Succession Through a Pipe: Example

This scenario assumes that the application controlling RMAN wants to run multiple commands in succession. After each command is sent down the pipe and executed and the output returned, RMAN pauses and waits for the next command.

To execute RMAN commands through a pipe:

1. Start RMAN by connecting to a target database (required) and specifying the PIPE option. For example, issue:

   % rman PIPE abc TARGET /
   

   You can also specify the TIMEOUT option, which forces RMAN to exit automatically if it does not receive any input from the input pipe in the specified number of seconds. For example, enter:

   % rman PIPE abc TARGET / TIMEOUT 60
   

2. Connect to the target database and put the desired commands on the input pipe by using DBMS_PIPE.PACK_MESSAGE and DBMS_PIPE.SEND_MESSAGE. In pipe mode, RMAN issues message RMAN-00572 when it is ready to accept input instead of displaying the standard RMAN prompt.

3. Read the RMAN output from the output pipe by using DBMS_PIPE.RECEIVE_MESSAGE and DBMS_PIPE.UNPACK_MESSAGE.

4. Repeat Steps 2 and 3 to execute further commands with the same RMAN instance that was started in Step 1.

5. If you used the TIMEOUT option when starting RMAN, then RMAN terminates automatically after not receiving any input for the specified length of time. To force RMAN to terminate immediately, send the EXIT command.

Executing RMAN Commands in a Single Job Through a Pipe: Example

This scenario assumes that the application controlling RMAN wants to run one or more commands as a single job. After running the commands that are on the pipe, RMAN exits.

To execute RMAN commands in a single job through a pipe:

1. After connecting to the target database, create a pipe (if it does not exist under the name ORA$RMAN_pipe_IN).

2. Put the desired commands on the input pipe. In pipe mode, RMAN issues message RMAN-00572 when it is ready to accept input instead of displaying the standard RMAN prompt.

3. Start RMAN with the PIPE option, and specify TIMEOUT 0. For example, enter:

   % rman PIPE abc TARGET / TIMEOUT 0
   

4. RMAN reads the commands that were put on the pipe and executes them by using DBMS_PIPE.PACK_MESSAGE and DBMS_PIPE.SEND_MESSAGE. When it has exhausted the input pipe, RMAN exits immediately.

5. Read RMAN output from the output pipe by using DBMS_PIPE.RECEIVE_MESSAGE and DBMS_PIPE.UNPACK_MESSAGE.

   See Also:

   Oracle Database PL/SQL Packages and Types Reference for documentation on the DBMS_PIPE package