Removing the Oracle Grid Infrastructure Home

After removing the Oracle Grid Infrastructure software, if you want to deinstall the previous release Oracle Grid Infrastructure home, then you must first change the permission and ownership of the previous release Grid home.

As the root user, change the permission and ownership of the previous release Grid home using the following command syntax, where oldGH is the previous release Grid home, giowner is the Oracle Grid Infrastructure installation owner, and oldGHParent is the parent directory of the previous release Grid home:
```
#chmod -R 755 oldGH
#chown -R giowneroldGH
#chown giowneroldGHParent
```
For example:
```
#chmod -R 755 /u01/app/21.0.0/grid
#chown -R grid /u01/app/21.0.0/grid
#chown grid /u01/app/21.0.0/
```
As the grid user, and use the -checkonly parameter from previous release Grid home oldGH /deinstall directory to check the status of the Oracle software home configuration.
```
oldGH/deinstall/deinstall -checkonly -silent -o /tmp/ -tmpdir /tmp
```
Use the deinstall command from previous release Grid home oldGH /deinstall directory to deinstall the previous release Grid home.
```
oldGH/deinstall/deinstall -silent -tmpdir /tmp/rsp_file
```
As the root user, run the rootdeinstall.sh script from the /tmp/deinstall / directory.
```
/tmp/deinstall/rootdeinstall.sh
```
Caution:
You must use the deinstall command from the same release to remove Oracle software. Do not run the deinstall command from a later release to remove Oracle software from an earlier release. For example, do not run the deinstall command from the 23.0.0.0.0 Oracle home to remove Oracle software from an existing 21.0.0.0.0 Oracle home.