How to clone an Oracle 10g ORACLE_HOME easily

Last Friday I had been working very hard to install Oracle 10g software on no less than 8 servers. This included 1 ORACLE_HOME for ASM, and 2 separate ORACLE_HOMEs per machine for the separated databases to be installed and configured. So, in total a number of 24 installations of 10.2.0.1 and on top of that 24 times the 10.2.0.3 patch set.There should be an easier way to do this, I thought. With my Oracle E-Business Suite background, I know it is possible to clone an RDBMS ORACLE_HOME, but EBS uses specific scripts for this procedure, and this was not EBS; just plain Oracle Database Software.
I started googling around, and found out there is a perl script, delivered with Oracle 10g, to clone the ORACLE_HOME. It is located in $ORACLE_HOME/clone/bin (where have I seen this kind of directories earlier..?). It turns out to be really easy to clone an ORACLE_HOME.
Here are the steps, including the expected output:

1. Copy the Oracle_HOME to the destination location (whether it be on the same or a remote server). When you need to rename the directory where the current installation is located, you can do this as well. If necessary, take the central inventory as well.

2. Check the existence of the ORACLE_HOME in the Central Inventory

$ pwd/appora/oraInventory/ContentsXML$ grep
"HOME NAME" *inventory.xml:
$

3. (Conditional) Detach the ORACLE_HOME using runInstaller from the copied ORACLE_HOME

$ $ORACLE_HOME/oui/bin/runInstaller
-detachhome ORACLE_HOME=/appora/product/10.2.0/db
Starting Oracle Universal
Installer...

No pre-requisite checks found in oraparam.ini, no
system pre-requisite checks will be executed.
The inventory pointer is located at
/var/opt/oracle/oraInst.loc
The inventory is located at
/appora/oraInventory'
DetachHome' was successful.
$

4. Check the Inventory to see if the ORACLE_HOME was removed (verify the REMOVED=”T” option is added to the ‘HOME NAME’ tag)

$ cd /appora/oraInventory/ContentsXML
$ grep "HOME NAME" *
inventory.xml:
$

5. Reregister the ORACLE_HOME
Make sure nothing by the current user is running, because it will do a relink as part of the procedure.

$ cd $ORACLE_HOME/clone/bin
$ perl clone.pl ORACLE_HOME="/appora/product/10.2.0/db" ORACLE_HOME_NAME="OraDb10g_home1"
./runInstaller -silent -clone -waitForCompletion "ORACLE_HOME=/appora/product/10.2.0/db"
"ORACLE_HOME_NAME=OraDb10g_home1" -noConfig -nowait
Starting Oracle Universal Installer...
No pre-requisite checks found in oraparam.ini, no system pre-requisite checks will be executed.
Preparing to launch Oracle Universal Installer from /tmp/OraInstall2008-11-07_03-21-26PM.
Please wait ...Oracle Universal Installer, Version 10.2.0.3.0 Production

Copyright (C) 1999, 2006, Oracle. All rights reserved.

You can find a log of this install session at:
/appora/oraInventory/logs/cloneActions2008-11-07_03-21-26PM.log
....................................................................................................
100% Done.

Installation in progress (Fri Nov 07 15:21:37 CET 2008)
.................................................................................
81% Done.

Install successful

Linking in progress (Fri Nov 07 15:21:49 CET 2008)
Link successful

Setup in progress (Fri Nov 07 15:22:56 CET 2008)
Setup successful

End of install phases.(Fri Nov 07 15:23:03 CET 2008)
WARNING:
The following configuration
scripts need to be executed as the "root" user.
#!/bin/sh
#Root script to run
/appora/product/10.2.0/db/root.sh
To execute the configuration scripts:
1. Open a terminal window
2. Log in as "root"
3. Run the scripts

The cloning of OraDb10g_home1 was successful.
Please check '/appora/oraInventory/logs/cloneActions2008-11-07_03-21-26PM.log' for more
details.
$

6. Run Root.sh

$ su -
Password:
#
# /appora/product/10.2.0/db/root.sh
Running Oracle10 root.sh script...
The following environment variables are set as:
ORACLE_OWNER= oracle
ORACLE_HOME= /appora/product/10.2.0/db
Enter the full pathname of the local bin directory: [/usr/local/bin]:
The file "dbhome" already exists in /usr/local/bin. Overwrite it? (y/n) [n]: y
Copying dbhome to /usr/local/bin ...
The file "oraenv" already exists in /usr/local/bin. Overwrite it? (y/n) [n]: y
Copying oraenv to /usr/local/bin ...
The file "coraenv" already exists in /usr/local/bin. Overwrite it? (y/n) [n]: y
Copying coraenv to /usr/local/bin
...
Entries will be added to the /var/opt/oracle/oratab file as needed by
Database Configuration Assistant when a database is created
Finished running generic part of root.sh script.
Now product-specific root actions will be performed.
#

7. The clone is ready now.

The nice thing about this is that once you have an ORACLE_HOME with a number of patches (like I had with the 10.2.0.3 patch set) these will automatically be taken with the clone.