Unlocking and Deinstalling the Previous Release Grid Home

After upgrading from previous releases, 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.

Unlock the Oracle Grid Infrastructure installation using the following procedure:

Log in as root, and 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 giowner oldGH
#chown giowner oldGHParent
```
For example:
```
#chmod -R 755 /u01/app/18.0.0/grid
#chown -R grid /u01/app/18.0.0/grid
#chown grid /u01/app/18.0.0
```
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<date>/ directory.
```
/tmp/deinstall<date>/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 19.0.0.0.0 Oracle home to remove Oracle software from an existing 18.0.0.0.0 Oracle home.

Parent topic: Upgrading Oracle Grid Infrastructure