An Oracle ASM instance does not have a data dictionary, so the only way to connect to an Oracle ASM instance is by using one of three system privileges, SYSASM, SYSDBA, or SYSOPER. There are three modes of connecting to Oracle ASM instances:
Local connection using operating system authentication
Local connection using password authentication
Remote connection by way of Oracle Net Services using password authentication
Your operating system-specific Oracle Grid Infrastructure Installation Guide for information about how to ensure that the Oracle ASM and database instances have member disk access
This section describes the following topics:
The Oracle ASM and database instances must have read/write operating system access rights to disk groups. For example, the Oracle ASM instance and the database instance must have identical read and write permissions for the disks that comprise the related Oracle ASM disk group. For Linux and UNIX systems, this is typically provided through shared Linux and UNIX group membership (OSASM group). On Windows systems, the Oracle ASM service must be run as Administrator. For information about file permissions and Oracle ASM File Access Control, see "Managing Oracle ASM File Access Control for Disk Groups".
Oracle Database Security Guide for information about maintaining database security, including assigning passwords