To create a grid installation owner account where you have an existing system privileges group (in this example, dba), whose members you want to have granted the SYSASM privilege to administer the Oracle ASM instance, enter a command similar to the following:

# /usr/sbin/useradd -u 1100 -g oinstall -G dba grid

In the preceding command:

• The -u option specifies the user ID. Using this command flag is optional, as you can allow the system to provide you with an automatically generated user ID number. However, you must make note of the user ID number of the user you create for Oracle Grid Infrastructure, as you require it later during preinstallation, and you must have the same user ID number for this user on all nodes of the cluster.

• The -g option specifies the primary group, which must be the Oracle Inventory group. For example: oinstall.

• The -G option specified the secondary group, which in this example is dba.

  The secondary groups must include the OSASM group, whose members are granted the SYSASM privilege to administer the Oracle ASM instance. You can designate a unique group for the SYSASM system privileges, separate from database administrator groups, or you can designate one group as the OSASM and OSDBA group, so that members of that group are granted the SYSASM and SYSDBA privileges to grant system privileges to administer both the Oracle ASM instances and Oracle Database instances. In code examples, this group is asmadmin.

  If you are creating this user to own both Oracle Grid Infrastructure and an Oracle Database installation, then this user must have the OSDBA for ASM group as a secondary group. In code examples, this group name is asmdba. Members of the OSDBA for ASM group are granted access to Oracle ASM storage. You must create an OSDBA for ASM group if you plan to have multiple databases accessing Oracle ASM storage, or you must use the same group as the OSDBA for all databases, and for the OSDBA for ASM group.