Most documents that describe the steps needed to clone an Oracle database using Grid Infrastructure (GI) assume that the GI is already installed on the target host, and that the ASM instance is up and running.
The standard way to do this is to install GI from the installation media from scratch, either using the graphical installer, or scripting the process by invoking the installer in silent mode. The installer is responsible for copying the software as well as for the configuration of the Oracle Clusterware and Oracle ASM. Once this step is completed and ASM is up on the target host, database volumes can be refreshed from the source database volumes using FlashArray™ snapshots.
A quicker approach would be to copy the source FlashArray volume where the Oracle Grid and Database software is installed. However, doing this will work only if the hostname of the target machine is the same as the source. This is because the Grid Infrastructure configuration files have the hostname hardcoded in them when they were originally created on the source. In practical situations, the target host name will need to be different from the source host name, which will cause ASM to break.
In this article, we will look at how we can get around this issue by resetting the Grid Infrastructure configuration files. This can significantly reduce the time it takes to create an Oracle ASM instance because now we can leverage FlashArray's instant volume copy to clone the Oracle Home and Grid Home as well. This technique really comes in handy when we are dealing with Oracle running in a virtualized environment because it's common to create a new virtual machine as a clone of an existing one.