Connecting to RMAN Tips

Connecting to RMAN

RMAN is an O/S level tool and is available at the $ORACLE_HOME/bin folder. If Oracle Home is not set, than you need to give a complete path for the binary to fire it up.  Otherwise, it can just be started by simply typing over the command (terminal over Linux) prompt as:

This would bring you to the RMAN prompt from where you can connect to the target database both by using or not using the recovery catalog. Note that just typing RMAN would not actually get you connected and you do need an explicit connect command to be given before you can use RMAN.

Connecting to RMAN Without Using Recovery Catalog

If you have not created the recovery catalog yet, you can still work with RMANwithout any issues. To connect to RMAN without using the catalog, all you need to do is pass on the target databases sys user name and its password with the correct network alias if you are firing up RMAN while sitting at another machine other than the actual server. All the following commands assume that you are on the same machine where the database is installed whom you want to backup.

This shows that you have been told by RMAN that you are not using the recovery catalog but the target databases control file. The switch nocatalog is the default option and can be skipped if you do not intend to use the catalog. If this would have been a client machine, you could use the connection string and the sys user with its password to get connected like below:

One thing which must have crossed your mind is that the above command displays the password wide open for any one which surely is not a good idea. This can be changed by just typing the user name sys and entering the password in the next line without it being displayed to anyone.

Connecting to RMAN using a Recovery Catalog

If you want to use RMAN with the recovery catalog, there is nothing much that you need to do except to use one switch with the user name and password of the catalog user. This user should be created in the catalog database.

This time, you are clearly told that you are using the catalog, not the control file of the target database. This topic is explained in detail in Chapter 8, Managing the Recovery Catalog?.

You can also use a log file for future reference to see all the commands and their outputs which you entered. By default, entire output is printed on the screen of the RMAN prompt itself, which would get lost once you close the session. Using the log file helps preserve that output for any kind of reference or debugging that you would like to do. The file can be written in the append mode as well so that the previously written content will not get erased.

Here is how you can use the log file. Note how nothing is printed on the rmans prompt but gets logged into the log file.

If you want to run some specific command while connecting to the RMAN prompt, you can do so by using the switch cmdfile parameter which is similar to running a SQL file while connecting to the SQL prompt. This does require a RMAN script file to be available which can be created using any editor of your choice. The file should be usable by the user who is running the RMAN with proper permissions and correct syntax. Here is a simple script that shows how it can be used while firing up RMAN.

If you are going to create a duplicate database, you can use the auxilary mode of the RMAN connection. Using this, you can connect to the auxilary instance, which is required to create a duplicate database. This can be done like this: 

This type of connection is described further in Chapter 5.