Each Oracle Database requires an operating system group to be designated as the OSDBA group. Members of this group are granted the SYSDBA system privileges to administer the database.
You must create an OSDBA group in the following circumstances:
An OSDBA group does not exist, for example, if this is the first installation of Oracle Database software on the system
An OSDBA group exists, but you want to give a different group of operating system users database administrative privileges for a new Oracle Database installation
Create the OSDBA group using the group name
dba, unless a group with that name already exists:
# /usr/sbin/groupadd -g 54322 dba