Required Operating System users and environment variables
The instance is a term that is used for a set of background processes and shared memory. The term database instance refers to a set of data that is stored on disk. An Oracle instance can mount and open a single database, and a database can be mounted and opened by one or more instances.
Often the Operating System (OS) user oracle has administrator permissions for databases in Oracle installations. IBM® Storage Protect Snapshot requires a dedicated OS user for each instance. The environment variables ORACLE_HOME and ORACLE_SID must be set permanently for that user, and refer to the instance that can be used to connect to the database that is to be protected by IBM Storage Protect Snapshot. The user requires administrator permissions.
If you want to protect one database on a host, and plan to use the backup server to back up only one database with one Oracle instance, you can reuse the oracle user. Set the ORACLE_SID variable to the instance that is used to connect to that database permanently on both the production server and the backup server in the oracle user profile.
If you want to protect multiple databases on one production or backup server host, you need one OS user per database on both the production server and backup server. This user ID is referred to as instance owner. The ORACLE_SID that is set in the environment for each OS user, enables SQL*Plus connections to the specific database to be protected by IBM Storage Protect Snapshot. Export the Oracle-specific environment variables, such as ORACLE_HOME and ORACLE_SID so that they are accessible when you enter the su - <instance_owner> -c command.