If you are planning to change the hostname and ipaddress of the standalone grid infrastructure ( oracle restart), then we need to do below deconfig and reconfig on the grid setup.

1. Stop the has

$GRID_HOME/bin/crsctl stop has

2 . Run the deconfig tool ( from root user )

export GRID_HOME=/gridapp/app/oracle/product/12.1.0.2/grid

$GRID_HOME/crs/install/roothas.pl -deconfig -force

[root@dbhost-prod ~]# /gridapp/app/oracle/product/12.1.0.2/grid/crs/install/roothas.pl -deconfig -force

Using configuration parameter file: /gridapp/app/oracle/product/12.1.0.2/grid/crs/install/crsconfig_params
2019/10/09 13:19:13 CLSRSC-337: Successfully deconfigured Oracle Restart stack

3. Run the reconfig script (from root user)

export GRID_HOME=/gridapp/app/oracle/product/12.1.0.2/grid

$GRID_HOME/root.sh

[root@dbhost-prod grid]# /gridapp/app/oracle/product/12.1.0.2/grid/root.sh
Performing root user operation.

The following environment variables are set as:
    ORACLE_OWNER= oracle
    ORACLE_HOME=  /gridapp/app/oracle/product/12.1.0.2/grid

Enter the full pathname of the local bin directory: [/usr/local/bin]:
The contents of "dbhome" have not changed. No need to overwrite.
The contents of "oraenv" have not changed. No need to overwrite.
The contents of "coraenv" have not changed. No need to overwrite.

Entries will be added to the /etc/oratab file as needed by
Database Configuration Assistant when a database is created
Finished running generic part of root script.
Now product-specific root actions will be performed.
Using configuration parameter file: /gridapp/app/oracle/product/12.1.0.2/grid/crs/install/crsconfig_params
LOCAL ADD MODE
Creating OCR keys for user 'oracle', privgrp 'oinstall'..
Operation successful.
LOCAL ONLY MODE
Successfully accumulated necessary OCR keys.
Creating OCR keys for user 'root', privgrp 'root'..
Operation successful.
CRS-4664: Node dbhost-prod successfully pinned.
2019/10/09 13:24:00 CLSRSC-330: Adding Clusterware entries to file 'oracle-ohasd.service'


dbhost-prod     2019/10/09 13:24:30     /gridapp/app/oracle/product/12.1.0.2/grid/cdata/dbhost-prod/backup_20191009_132430.olr     1721139106
CRS-2791: Starting shutdown of Oracle High Availability Services-managed resources on 'dbhost-prod'
CRS-2673: Attempting to stop 'ora.evmd' on 'dbhost-prod'
CRS-2677: Stop of 'ora.evmd' on 'dbhost-prod' succeeded
CRS-2793: Shutdown of Oracle High Availability Services-managed resources on 'dbhost-prod' has completed
CRS-4133: Oracle High Availability Services has been stopped.
CRS-4123: Oracle High Availability Services has been started.
2019/10/09 13:27:28 CLSRSC-327: Successfully configured Oracle Restart for a standalone server

4. Login with grid owner and modify css properties ( grid or oracle)

$ $GRID_HOME/bin/crsctl modify resource “ora.cssd” -init -attr “AUTO_START=1” -unsupported

5. Restart has

$ $GRID_HOME/bin/crsctl stop has
CRS-2791: Starting shutdown of Oracle High Availability Servic
es-managed resources on 'dbhost-prod'
CRS-2673: Attempting to stop 'ora.evmd' on 'dbhost-prod'
CRS-2677: Stop of 'ora.evmd' on 'dbhost-prod' succeeded
CRS-2793: Shutdown of Oracle High Availability Services-managed resources on 'dbhost-prod' has completed
CRS-4133: Oracle High Availability Services has been stopped.


$ $GRID_HOME/bin/crsctl start has
CRS-4123: Oracle High Availability Services has been started.

6. Check the resource status:

cd $GRID_HOME/bin

$ ./crsctl check has
CRS-4638: Oracle High Availability Services is online

$ ./crsctl check css
CRS-4529: Cluster Synchronization Services is online

$ ./crsctl stat resource
NAME=ora.cssd
TYPE=ora.cssd.type
TARGET=ONLINE
STATE=ONLINE on dbhost-prod

NAME=ora.diskmon
TYPE=ora.diskmon.type
TARGET=OFFLINE
STATE=OFFLINE

NAME=ora.evmd
TYPE=ora.evm.type
TARGET=ONLINE
STATE=ONLINE on dbhost-prod

NAME=ora.ons
TYPE=ora.ons.type
TARGET=OFFLINE
STATE=OFFLINE

$ ./crsctl stat res -t
--------------------------------------------------------------------------------
Name           Target  State        Server                   State details
--------------------------------------------------------------------------------
Local Resources
--------------------------------------------------------------------------------
ora.ons
               OFFLINE OFFLINE      dbhost-prod                STABLE
--------------------------------------------------------------------------------
Cluster Resources
--------------------------------------------------------------------------------
ora.cssd
      1        ONLINE  ONLINE       dbhost-prod                STABLE
ora.diskmon
      1        OFFLINE OFFLINE                               STABLE
ora.evmd
      1        ONLINE  ONLINE       dbhost-prod                STABLE
--------------------------------------------------------------------------------
$


7. Config the listener .

We are using 1521 default listener,so

srvctl add listener

srvctl start listener

8. Prepare and start asm instance:

create the asm pfile as below:

$ cat init+ASM.ora
+ASM1.__oracle_base='/gridapp/app/oracle'#ORACLE_BASE set from in memory value
*.asm_diskstring='/dev/oracleasm/disks/*'
*.asm_power_limit=16
*.large_pool_size=12M
*.instance_type='asm'


start the asm instance:

SQL> startup pfile=init+ASM.ora

SQL> select instance_name,status from gv$Instance;

INSTANCE_NAME STATUS
---------------- ------------
+ASM STARTED

SQL> select path from v$asm_disk;

PATH
--------------------------------------------------------------------------------
/dev/oracleasm/disks/MGMTD

SQL> create spfile from pfile;

File created.

Modify asm properties.

$ srvctl modify asm  -p /gridapp/app/oracle/product/12.1.0.2/grid/dbs/spfile+ASM.ora
$ srvctl modify asm  -l LISTENER
$ srvctl config asm
ASM home: 
Password file:
ASM listener: LISTENER
Spfile: /gridapp/app/oracle/product/12.1.0.2/grid/dbs/spfile+ASM.ora
ASM diskgroup discovery string: /dev/oracleasm/disks/*


9. Restart the has one more time:

$GRID_HOME/bin/crsctl stop has

$GRID_HOME/bin/crsctl start has 


Now our standalone grid infrastructure is back to normal.