Oracle patching secrets with $ORACLE_HOME cloning
Oracle Database Tips by Donald Burleson
Use Oracle home
Gold copy Cloning to Make Patches/Upgrades Easy, Quicker, Safer, and
With Less Downtime
By John Adolph Palinski
This article describes
benefits and techniques of using Oracle home gold copies and clones of these
homes. A gold copy Oracle Home is a master Oracle home whose function is to be
copied and deployed to other places for use as an Oracle home. Patching is done
on the gold copy rather than in-place production Oracle homes. Using a gold
Oracle home and cloning of the gold home can reduce the amount of time DBA's
spend applying quarterly critical patch updates (CPU's) and bug patches. Most
importantly cloning helps the DBA by reducing database downtime, easing the task
of scheduling outages, and eliminating the effect of problems that occur when
applying patches in-place.
A common DBA task is to patch
Oracle homes and databases. These patches can be one of the many bug fixes or
the quarterly CPU. Regardless of the reason, the following must be done for
every database the DBA is responsible for:
The DBA must move the patch software to the
server and unzip the file.
Make sure the environment is setup properly
to run Opatch.
Shutdown the listener and database.
Patch the Oracle home.
Restart the database and listener
Run Utlrp.sql to compile PL/SQL.
Step 4 is often a time
consuming and risky task. There are many possibilities that can cause the
Oracle home patch to fail. Some reasons are: incorrect patch versions, the
environment is not set up properly for Opatch, or a failure to stop some
processes using the Oracle home. Step 4 is performed when the database is down
and unavailable for the users. Thus, it is very important to the DBA that this
step NOT FAIL. If any problems occur in this step, the database outage is
increased and the DBA's stress and anxiety begin to grow geometrically. The DBA
has to try to identify the problem/solution or decide whether the patch should
be rolled back. This is where gold copy Oracle home cloning becomes the tool of
choice since the step is eliminated by cloning.
Gold copy Oracle home cloning
allows the DBA to patch a cloned Oracle home that is NOT USED by a running
database. If problems occur, the running database is not affected. Only AFTER
the cloned gold copy Oracle home is patched is it moved to the proper location
and the database brought down and pointed to the new Oracle home. If any
problems occur, the original Oracle home is still available allowing the DBA to
retreat and point the database back to the original home and if necessary
restore the database from backup.
In addition, Oracle home
cloning offers you the possibly of eliminating Steps 1, 2, and 4. This can be a
time saver, reduce outage time, and eliminate scheduling problems. It is
possible to create an Oracle home gold copy on a server in a compressed state
and move the gold copy to a target server. Patching a gold copy and moving this
copy to a target server can be a very effective tool. Let's look at some
In the first scenario, four
Oracle homes exist on different servers, each containing a single database. The
DBA must perform all of the seven steps listed above. Four outages need to be
planned and the DBA has to take the risk of patching an Oracle home in-place
four times. Scheduling is easy since each Oracle home patch is independent of
the others. If the DBA uses a cloned gold copy and moves the gold copy to each
server, time can be saved. FTPing a compressed gold copy to the target server
and uncompressing the gold copy usually takes less time than performing steps 1,
2, 3, and 4 on each home. More important, once the gold copy is uncompressed,
you have a valid Oracle home. You do not have to patch the Oracle home during
the outage. You don't have to run Opatch since it was done on the gold copy.
All that is necessary is to shut down the database, register the Oracle home
with the Oracle inventory, run Catcpu.sql, change the environment to point to
the new Oracle home, and start the database and listener. This will positively
result in less risk and shorter outages.
Scenario 2 is a common Oracle
home that supports a number of databases. This type of installation is often
used on data servers that support remote applications. A single Oracle home is
used in order to save disk space since one Oracle home takes far less disk space
that multiple Oracle homes.
Having a single Oracle home
makes patches/upgrades easier since only a single home must be modified. The
arrangement is prone to scheduling problems. It is often difficult to gain an
outage on a single database let alone four databases. Cloning makes this type
of environment effective by easing scheduling processes. If the DBA only has to
point the database toward the new cloned Oracle home and run Catcpu.sql against
the database, each database can be scheduled separately. Cloning makes this
possible. In addition, the cloning has the benefits discussed earlier. Figure
3 depicts the pointing of databases to the new cloned Oracle home while an
existing Oracle home still supports databases.
Now that you have seen the
benefits and reasons for using cloned gold Oracle homes for patches and
upgrades, how do you create an Oracle home gold copy and clone an Oracle home?
Actually it is very easy. If you have Oracle Enterprise Manager Grid Control
there is an option on the Deployments page. However, this function is disabled
unless you purchase one of the add-on packages. If you don't have OEM Grid
Control, take heart, it is very easy to clone an Oracle home from the command
line. The next section describes how this can be done.
Creating, Cloning, and
Deploying an Oracle home Gold Copy
Note that the steps and
commands in this section pertain to Oracle10g homes only.
- Make the initial Oracle
home gold copy. Download the appropriate Oracle database product, launch
the Oracle Universal Installer, and create an Oracle home. Do not create a
database. This Oracle home is the original gold copy version. It is only
used for patching and upgrading.
- Apply all appropriate
patches to initial Oracle home gold copy.
To clone or make a new
variation of the Oracle home gold copy, perform the following:
1. Create another gold copy Oracle home.
a) Navigate to the gold copy Oracle home parent
directory. In our case we will call this directory /u01/app/oracle/clones.
This directory contains the gold Oracle homes. The example gold Oracle home is
b) Make a CPIO archive of the target gold Oracle
home. Again, the target is a directory called 10.2.0.2.jan07. Replace this
gold Oracle home directory reference with yours. The below CPIO command makes a
CPIO file of the 10.2.0.2.jan07 Oracle home.
find ./10.2.0.2.jan07 -depth | cpio -voB >
c) Make a directory in the
/u01/app/oracle/clones directory to unpack the 10.2.0.2.jan07.cpio file created
in step b.
d) Unpack the 10.2.0.2.jan07.cpio file into the
/u01/app/oracle/clones/tmp directory. First navigate into the tmp directory and
issue a Cpio command. The commands are:
cd /tmp or cd /u01/app/oracle/clones/tmp
cpio -invd < ../10.2.0.2.jan07
e) Step D created a
/u01/app/oracle/clones/tmp/10.2.0.2.jan07 directory. You need to rename the
10.2.0.2.jan07 and move it down a directory. Use this command:
f) Step E creates an unregistered Oracle home
locate in /u01/app/oracle/clones/10.2.0.2.jan07b. This step registers the new
home with Oracle inventory. Run these commands:
perl $ORACLE_HOME/clone/bin/clone.pl \
You now have a cloned, renamed replica of the
original Oracle gold copy home (10.2.0.2.jan07). If you run Oracle Universal
Installer, you will see that the clone is registered. You can now add patches
to this home without affecting the original gold home. After patching, you may
want to create a CPIO archive, compress the archive, and delete the actual
Oracle home. This will save space. The CPIO?d gold copy can be restored at any
point for further cloning and moved to other servers for use. You might note
that all of the work was done remotely and does not affect an operating
To move a gold copy Oracle home to another
location, perform the following:
1. Create a compressed CPIO archive of the
Oracle home gold copy (Steps A and B above)
2. FTP the compressed CPIO archive to the new
server. Place the file in the Oracle homes parent directory (i.e.
3. Uncompress and unpack the CPIO gold copy
cpio -imvd < 10.2.0.2.jan07b.cpio
4. Register the database with Oracle Inventory.
Perform Step e. If this is the first Oracle Home on the server, you must
install an Oracle home with Universal Installer before trying to register the
cloned Oracle home. This will create the inventory. You can delete the home
after creation and use the clone.
5. At this point, the cloned Oracle home is
ready to support a database. You can install a new database for the Oracle home
by running Oracle Database Configuration Agent or point an existing database to
the new Oracle home. The following steps can be used to point an existing
database to the new Oracle home.
a. Modify the environment file (inst.ksh) so that
the environment will point to the new Oracle home.
b. Modify the listener file (listener.ora) to
point to the new Oracle home.
c. Modify the Etc/oratab file
d. Shutdown the database. Change the environment
to the new Oracle home and reload the listener.
e. Move the old database's pfile/spfile to the
location used by the new Oracle home.
f. Start the database
g. If this Oracle home is a patched version run
h. Create a new password file
i. Check out the upgraded database.
In this article I discussed the benefits of using
a gold copy Oracle home and cloning in place of patching an Oracle home in
place. You will find that this practice reduces the patching complexities,
risk, and time. Using a cloned gold copy will also result in less outage time.
Cloning can be done through Oracle Enterprise Manager Grid Control. If this
tool is unavailable, the article describes a set of simple commands that will
enable you to create and deploy cloned Oracle homes. I believe that employment
of the techniques discussed in this article will make you life as a DBA easier.
John Adolph Palinski is a former adjunct faculty
member at the University of Nebraska at Omaha and Iowa Western Community
College. He is the author of the "Oracle Database Construction Kit", Que, 1997,
the "Oracle SQL and PL/SQL Handbook: A Guide for Data Administrators,
Developers, and Business Analysts", Addison Wesley Longman, 2002, and "Oracle 9i
Developer: Developing Web Applications With Forms Builder", Course Technology,
2003. He has also written numerous articles for periodicals such as Oracle
Internals and Oracle Professional. He provides Oracle training and consulting
services. One of his passions is to help customers set up logical business
models to improve information efficiency and effectiveness. John also works as
an instructor and consultant for Burleson Enterprises.
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