Removing Old Oracle Homes

De-Install has some bugs ..and it is touching a lot of files... and we do have enough control.
More controlled way ... is to simply detach the old Oracle home... and removing the root directory.

Step 1:  Set Oracle Home to Old Oracle Home ... and list all the available ORacle Homes.
[oracle@host1 product]$ export ORACLE_HOME=/u01/app/oracle/product/11.2.0.2/db_1
[oracle@host1 product]$ $ORACLE_HOME/OPatch/opatch lsinventory -all

Oracle Interim Patch Installer version 11.2.0.1.9
Copyright (c) 2011, Oracle Corporation.  All rights reserved.
Oracle Home       : /u01/app/oracle/product/11.2.0.2/db_1
Central Inventory : /u01/app/oraInventory
   from           : /u01/app/oracle/product/11.2.0.2/db_1/oraInst.loc
OPatch version    : 11.2.0.1.9
OUI version       : 11.2.0.2.0
Log file location : /u01/app/oracle/product/11.2.0.2/db_1/cfgtoollogs/opatch/opatch2014-03-26_17-00-52PM.log
Lsinventory Output file location : /u01/app/oracle/product/11.2.0.2/db_1/cfgtoollogs/opatch/lsinv/lsinventory2014-03-26_17-00-52PM.txt
--------------------------------------------------------------------------------
List of Oracle Homes:
  Name          Location
   OraDb11g_home2         /u01/app/oracle/product/11.2.0.2/db_1    ---- This is the Old home in the inventory… We need to remove this from the Central Inventory
   agent12g1         /u01/app/oracle/agent11g/core/12.1.0.1.0
   sbin12g1         /u01/app/oracle/agent11g/sbin
   Ora11g_gridinfrahome1         /u01/app/11.2.0.3/grid
   OraDb11g_home1         /u01/app/oracle/product/11.2.0.3/db_1
   agent11g1         /u01/app/oracle/agent11g/agent11g
   agent11g2         /u01/app/oracle/OEM11G/Middleware/agent11g
   common11g2         /u01/app/oracle/OEM11G/Middleware/oracle_common
   webtier11g2         /u01/app/oracle/OEM11G/Middleware/Oracle_WT

There are no Interim patches installed in this Oracle Home.
Rac system comprising of multiple nodes
  Local node = host1
  Remote node = host2
  Remote node = host3
--------------------------------------------------------------------------------
OPatch succeeded.

Step 2 :  Detach the home that we want to remove from the system.
[oracle@host1 product]$ $ORACLE_HOME/oui/bin/runInstaller -detachHome -silent ORACLE_HOME=/u01/app/oracle/product/11.2.0.2/db_1
Starting Oracle Universal Installer...

Checking swap space: must be greater than 500 MB.   Actual 65535 MB    Passed
The inventory pointer is located at /etc/oraInst.loc
The inventory is located at /u01/app/oraInventory
'DetachHome' was successful.


Step 3:  Double Check if the home still exists in the inventory.

--------------------------------------------------------------------------------
List of Oracle Homes:
  Name          Location
   agent12g1         /u01/app/oracle/agent11g/core/12.1.0.1.0
   sbin12g1         /u01/app/oracle/agent11g/sbin
   Ora11g_gridinfrahome1         /u01/app/11.2.0.3/grid
   OraDb11g_home1         /u01/app/oracle/product/11.2.0.3/db_1
   agent11g1         /u01/app/oracle/agent11g/agent11g
   agent11g2         /u01/app/oracle/OEM11G/Middleware/agent11g
   common11g2         /u01/app/oracle/OEM11G/Middleware/oracle_common
   webtier11g2         /u01/app/oracle/OEM11G/Middleware/Oracle_WT

Installed Top-level Products (1):

Oracle Database 11g                                                  11.2.0.3.0
There are 1 products installed in this Oracle Home.


Step 4 : You are now good to delete the Oracle home using rm –rf . Pls note that many files in GRID_HOME will be owned by root. So,  its better to do it from Root user.

/bin/rm -rf $OLD_GI_HOME
Before removing the directories, I rename them to XYZ … , bounced all the services .. CRS/ASM/DBs … made sure everything is working … kind of a fool proof…