Applying Patches Using Zero-Downtime Oracle Grid Infrastructure Patching

Starting with Oracle Database 19c Release Update (RU) 19.8, you can keep your Oracle RAC database instances running and accessible to the database users during Oracle Grid Infrastructure patching.

Use the switchGridHome command to switch from the current Oracle Grid Infrastructure home to the patched Oracle Grid Infrastructure home. Refer My Oracle Support note 2635015.1 for more information about zero-downtime Oracle Grid Infrastructure 19c patching. You can use the switchGridHome command only to switch between different RUs of the same release, for example from Oracle Grid Infrastructure 19.3 to Oracle Grid Infrastructure 19.8.

Note:

You can use zero-downtime patching only for out-of-place patching of Oracle Grid Infrastructure 19c Release Update (RU) 19.8 or later releases with Oracle RAC or Oracle RAC One Node databases of 19c or later releases. If your Oracle RAC or Oracle RAC One Node database release is older than 19c, then the database instances stop during zero-downtime patching.

Download the Oracle Database Release Update (RU) 19.8 or later from My Oracle Support.
As the grid user, download the Oracle Grid Infrastructure 19c image files and extract the files into a new Oracle Grid Infrastructure home directory.
```
$ mkdir -p /u01/app/19.8.0/grid
$ chown grid:oinstall /u01/app/19.8.0/grid
$ cd /u01/app/19.8.0/grid
$ unzip -q download_location/grid.zip
```
Note:
The new Oracle Grid Infrastructure home path must be different from the current Oracle Grid Infrastructure home path.
Start the Oracle Grid Infrastructure installer with the -switchGridHome flag to switch to the patched Oracle Grid Infrastructure home after the installation.
```
$ /u01/app/19.8.0/grid/gridSetup.sh -switchGridHome 
[-applyRU patch_directory_location] [-applyOneOffs comma_seperated_list_of_patch_directory_locations]
```
Follow the steps in the configuration wizard to complete the Oracle Grid Infrastructure installation.
During configuration, do not select the option to Automatically run configuration scripts.
When prompted, run the root.sh script with the -transparent and -nodriverupdate flags on the first node.
Run the root.sh script with the -transparent and -nodriverupdate flags on all other nodes.
All Oracle Grid Infrastructure services start running from the new Grid home after the installation is complete.

Verify that the patching has completed.

$ crsctl query crs activeversion -f
Oracle Clusterware active version on the cluster is [19.0.0.0.0]. The cluster upgrade state is [NORMAL]. 
The cluster active patch level is [patch_level].

Parent topic: Patching Oracle Grid Infrastructure