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Oracle® Real Application Clusters Installation Guide
12c Release 1 (12.1) for Linux and UNIX

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1 Preinstallation Checklist

This chapter is intended for database administrators to use in consultation with system and storage administrators to coordinate the installation and plan the tasks for Oracle Clusterware, in preparation for completing an installation of Oracle Real Application Clusters (Oracle RAC). This chapter contains the following topics:

1.1 Before You Start: Planning Your Installation

This section provides a list of tasks that Oracle recommends you complete before starting Oracle Clusterware and Oracle RAC installation. Whether your location is a data center with a large project team of system administrators, storage administrators, network administrators, database administrators, and third-party hardware and software vendors, or you are a project team of one, planning is important to help ensure that your installation proceeds smoothly.

It is beyond the scope of this documentation set to advise how to determine hardware sizing or capacity planning for your installation. Note that with Oracle Clusterware and Oracle RAC, you can add nodes and instances as needed in response to testing, or in response to increased workloads.

Review and complete the following steps as part of your installation plan:

1.1.1 Check My Oracle Support

Before you decide whether to install Oracle Database 12c Release 1 (12.1), log on to My Oracle Support:

You must register online before using My Oracle Support.


Contact your Oracle Sales Representative if you do not have a My Oracle Support account.

To access certifications for your installation:

  1. Log on to My Oracle Support.

  2. Click the Certifications tab. If you do not see a tab titled Certifications, then click More and select Certifications from the list.

  3. In the Certification Search frame, select Oracle Real Application Clusters, select the release number, and select your operating system platform on which you intend to install. When you have completed your selections, click Search to generate a product certification list for your installation.

1.1.2 Check Oracle Technology Network

The Oracle Technology Network (OTN) contains white papers about deployment options, capacity planning, best practices on various NFS platforms, and extended clusters deployments, which are not addressed in this guide. You can review available papers at the following website:

In particular, check the Oracle RAC Technologies Certification Matrix for your platform:



1.1.3 Review Installation Steps for Oracle RAC

Installing Oracle RAC consists of the following steps:

  1. Prepare servers (system, users and groups, network, and storage administration), as described in Oracle Grid Infrastructure Installation Guide for your platform. These tasks include the following:

    • Install the operating system and install the operating system packages and patches to the required version.

    • Create the required groups, users, and software homes.

    • Set up the domain name forwarding for Grid Naming Service (GNS) if you plan to deploy GNS or Multi-Cluster GNS, and set up the network addresses in the DNS and on the server as needed, depending on the cluster node type (Standard, Hub, Leaf) that you plan to configure for each node.

    • Set up the required storage.

    • (Optional) Stage all of the software on one node for installation (the "local node").


      During Oracle Grid Infrastructure installation, you can select multiple interconnects for private network use. This feature is called Redundant Interconnect Usage.

      With Redundant Interconnect Usage, Oracle Clusterware can define multiple interfaces to use for the cluster interconnect network, without the need of using bonding or other technologies.

      When you define multiple interconnects, either during the installation interview or afterward using the Oracle Interface Configuration (OIFCFG) command line utility, Oracle Clusterware creates from one to four highly available IP (HAIP) addresses. Oracle RAC and Oracle Automatic Storage Management (Oracle ASM) instances use these interconnect addresses to ensure highly available, load-balanced interconnect communication between nodes.

      See Also:

      Oracle Clusterware Administration and Deployment Guide for more information about using OIFCFG to modify interconnects, and Oracle Grid Infrastructure Installation Guide for your platform for more information about network configuration requirements
  2. Install Oracle Grid Infrastructure for a cluster, which includes Oracle Clusterware and Oracle ASM (system and storage administration):

    During installation, Fixup scripts perform additional configuration of operating system parameters, secure shell (SSH) for installation and user environment variables.

    • To configure Oracle RAC on an Oracle Flex Cluster, Oracle Grid Infrastructure for a cluster must be installed and configured in Oracle Flex Clusters mode.


    • You must have Oracle Grid Infrastructure installed successfully before you attempt to install Oracle RAC.

    • For Oracle Flex Clusters deployments, you cannot install Oracle RAC binaries on Oracle Automatic Storage Management Cluster File System (Oracle ACFS).

  3. Install Oracle RAC (database administration):

    • Install Oracle RAC or Oracle RAC One Node.

    • Complete the postinstallation configuration of the Oracle RAC database.

1.1.4 Review Documentation

Before installing Oracle RAC, review Oracle Grid Infrastructure Installation Guide for your operating system platform to confirm that all cluster member nodes are configured with required users and groups, and that the system, storage, and network administrators have completed any other tasks required for an Oracle RAC installation.

In addition, review the Release Notes and My Oracle Support ( to ensure that you have the most current information about system requirements and other information that can affect your installation. The small amount of time that this review takes can save a much greater amount of time required to track down causes of installation errors later. Also, verify that you have the most current version of this document; Oracle documentation is updated after the initial release and posted to the following web site:

Oracle recommends that you install a Web browser on your cluster nodes, both to enable Oracle Enterprise Manager and Oracle Application Express, and to access online documentation as needed. Online documentation is available in PDF and HTML formats.

See Also:

1.1.5 Select a Security Notification Contact

Oracle issues security alerts as needed for vulnerability fixes that are determined to be too critical to wait for distribution in the next Critical Patch Update.

During installation, you are asked in the Configure Security Updates screen to provide a security contact. Select one of the following options:

  • Provide an e-mail address to receive security information for your installation.

  • Provide a My Oracle Support e-mail address or account name to receive security information for your installation, and to enroll your system for Security Updates. You can receive information about alerts through My Oracle Support.

You can choose not to provide this information, but Oracle strongly recommends that you configure a security notification contact.

The information collected by Security Updates is limited to configuration information. The data collected does not include personally identifiable information (with the exception of a local contact name in case of transmission problems). You may still use all licensed Oracle functionality if you decline to enable Security Updates.If you prefer not to receive security notifications, then leave all fields in the Configure Security Updates screen blank, and click Next to continue.

If you provide your My Oracle Support credentials, then Security Updates automatically gathers configuration information regarding your installed Oracle products and uploads it to Oracle's support systems. You can access the information it collects through your My Oracle Support account, and review health check recommendations, patch recommendations and other recommendations for your system in addition to security alerts.

See Also:

The Oracle Security Policies page, which is available from the following URL:

1.1.6 Consider Using Software Updates Option

Oracle Universal Installer (OUI) can install patch updates, system requirement updates for supported operating systems, and other significant updates that can ensure that your installation succeeds. Oracle recommends that you enable the Software Updates option on the Download Software Updates screen during installation.

If you choose to enable the Software Updates option, then you must provide a valid My Oracle Support user name and password, so that OUI can download the latest updates, or you must provide a path to the location of a Software Updates option package that you have downloaded previously.

In addition, if you have a proxy realm, then be prepared to provide the destination proxy realm, and the user authentication (user name and password) required to authenticate access through that realm to the Internet, so that OUI can obtain software updates. Check with your network administrator before installation if you do not have this information.

If you plan to run the installation in a secured data center, then you can download updates before starting the installation by starting OUI on a system that has Internet access. To start OUI to download updates only, enter the following command:

$ ./runInstaller -downloadUpdates

Provide the My Oracle Support user name and password, and provide proxy settings if needed. After you download updates, transfer the update file to a directory on the server where you plan to run the installation.

1.1.7 Review Root Task Delegation Options With Your System Administrator

During installation, Oracle Universal Installer (OUI) requires you to run scripts with superuser (or root) privileges to complete many system configuration tasks.

1.1.8 Review Installation Fixup Scripts With Your System Administrator

During an installation, OUI detects when the minimum requirements for an installation are not met, and creates shell scripts, called fixup scripts, to finish incomplete system configuration steps. If OUI detects an incomplete task, then it generates fixup scripts ( You must run these scripts as root.

You can run the fixup script after you click Fix and Check Again. The fixup script modifies both persistent parameter settings and parameters in memory, so you do not need to restart the system, and can proceed with the installation.

1.1.9 Review How to Use Cluster Verification Utility (CVU)

You can use CVU before running OUI to ensure that your cluster is prepared for an Oracle RAC installation. CVU is incorporated into the installer, so CVU runs when you start an Oracle RAC installation. However, you can use CVU to ensure that any packages or configuration information that is required for Oracle RAC are in place before you begin your Oracle RAC installation.

Oracle provides CVU to perform system checks in preparation for an installation, patch updates, or other system changes. In addition, CVU can generate fixup scripts, which are scripts run by the root user that can change many kernel parameters to at least the minimum settings required for a successful installation.

Using CVU can help system administrators, storage administrators, and database administrators to ensure that everyone has completed the system configuration and preinstallation steps, so that installations, updates, or patches complete successfully. You can obtain the latest version of CVU at the following URL:

If you have a vendor who is performing hardware or operating system configuration steps, then ask the vendor to complete the relevant CVU check of the cluster after they complete their work to ensure that your system is configured correctly. Database administrators should refer to the section "Confirming Cluster Readiness for Oracle RAC Installation with CVU" to confirm that their system is prepared for installation before they start an Oracle RAC installation.

1.1.10 Review Existing Oracle Installations and Upgrade Plans

If you have an existing Oracle installation, then document version numbers, patches, and other configuration information, and review upgrade procedures for your existing installation. Review the Oracle upgrade documentation before proceeding with installation, to decide how to proceed.

To install Oracle RAC 12c Release 1 (12.1), you must have Oracle Grid Infrastructure (Oracle Clusterware and Oracle ASM) 12c Release 1 (12.1) installed on your cluster. The Oracle Clusterware version must be equal to or greater than the Oracle RAC version that you plan to install.

For the most current updates and best practices about pre-upgrade, post-upgrade, compatibility, and interoperability discussions, refer to "Oracle Upgrade Companion" for this release. "Oracle Upgrade Companion" is available through Note 1462240.1 on My Oracle Support:

For upgrades, note the following:

  • You can have only one version of Oracle Clusterware running on a cluster at a time. The Oracle Clusterware version must be the most recent release of any software (Oracle Clusterware, Oracle Database, Oracle RAC and Oracle Automatic Storage Management) running on the cluster. Before upgrading your database to Oracle Database 12c Release 1 (12.1), all nodes in the cluster must be upgraded to Oracle Clusterware and Oracle ASM 12c Release 1 (12.1).

  • You can have multiple Oracle homes for Oracle Databases on your cluster. However, the Oracle RAC database software in these homes must be from a version that is equal to or before the version of Oracle Clusterware that is installed; you cannot have a version of Oracle Database running on Oracle Clusterware that was released after the version of Oracle Clusterware that you are running.

    For example:

    • If your servers are running Oracle Grid Infrastructure 12c Release 1 (12.1), then you can have an Oracle Database 12c Release 1 (12.1) single-instance database running on one node, and separate Oracle RAC 11g Release 1 or 2, or Oracle RAC 12c Release 1 (12.1) databases also running on the cluster.

    • You cannot have Oracle Grid Infrastructure 11g Release 2 installed on your cluster, and install Oracle RAC 12c Release 1 (12.1).

  • You can use Database Upgrade Assistant (DBUA) for patch set upgrades with Oracle RAC. You can also use DBUA to upgrade between major point releases of Oracle RAC. For example, you can upgrade from Oracle Database 11g Release 2 (11.2) to Oracle Database 12c Release 1 (12.1).

  • You cannot change the owner of the Oracle Database home during an upgrade. You must use the same Oracle software owner that owns the existing Oracle Database home.

  • If you are upgrading an existing Oracle RAC installation, then you must use the same type of Oracle home that you have in your existing installation. For example, if you have a shared Oracle home in your existing installation, then you must upgrade to a shared Oracle home with Oracle RAC 12c Release 1 (12.1).

    Similarly, if you have local Oracle homes on cluster nodes, then you must upgrade to local Oracle homes on cluster nodes.

  • For the Oracle RAC database being upgraded, each cluster member node that hosts an instance of the database must be a member of the upgraded installation. For example, if you have an existing Oracle RAC database running on a three-node cluster, then you must upgrade Oracle RAC on all three nodes. You cannot upgrade only two nodes of the cluster, and then remove the third node and instance in the upgrade.

  • If you have any database data stored on RAW devices, then before you start Oracle Grid Infrastructure and Oracle RAC installation, you must use RMAN to copy that data to Oracle ASM or to another supported file system.

  • As with any system change, follow common industry standards for data recovery planning, and back up your existing database before upgrading your software.

1.1.11 Consider Memory Allocation and Automatic Memory Management

During a Typical installation, you create your database with Database Configuration Assistant (DBCA), and automatic memory management is enabled. If you choose advanced installation, then you can either specify memory allocation manually, or enable automatic memory management.

With automatic memory management, the Oracle RAC instances automatically manage and tune memory for you. With automatic memory management, you choose a memory target, and the instance automatically distributes memory between the system global area (SGA) and the instance program global area (instance PGA). As memory requirements change, the instance dynamically redistributes memory between the SGA and instance PGA.

If you choose not to enable automatic memory management during installation, then you can enable it after installation. Enabling automatic memory management after installation involves a shutdown and restart of the database.

See Also:

Oracle Database Administrator's Guide for more information about automatic memory management

1.1.12 Review Globalization Requirements

Before you start an installation on which you want to support languages other than English, review Oracle Database Globalization Support Guide.

Note the following:

  • Oracle recommends that you use Unicode AL32UTF8 as the database character set.

    Unicode is the universal character set that supports most of the currently spoken languages. Unicode also supports many historical scripts (alphabets). Unicode is the native encoding of many technologies, including Java, XML, XHTML, ECMAScript, and LDAP. Unicode is ideally suited for databases that support the Internet and the global economy.

  • The locale setting of your operating system session determines the language of the user interface and the globalization behavior for components such as Oracle Universal Installer, Oracle Net Configuration Assistant, and Database Configuration Assistant. The locale setting also determines the globalization behavior of Oracle Database sessions created by a user application through Oracle JDBC driver, unless overridden by the application.

  • The character set specified by the NLS_LANG environment variable determines the language of the user interface and the globalization behavior for components such as SQL*Plus, exp, and imp. This variable also sets the language and territory used by the client application and the database. The variable also declares the character set for entering and displaying data by the client application.

    The NLS_LANG environment variable should reflect the setting of the operating system character set of the client. For example, if the database character set is AL32UTF8 and the client is running on a Windows operating system, then you should not set the NLS_LANG environment variable to AL32UTF8 because there are no UTF-8 WIN32 clients. Instead, the NLS_LANG setting should reflect the code page of the client. For example, on an English Windows client, the code page is 1252, so an appropriate setting for NLS_LANG is AMERICAN_AMERICA.WE8MSWIN1252.


Oracle Database Installation Guide for your platform contains a more complete discussion of database character sets used with different languages, and provides further information about installing and configuring Oracle Database globalization support.

1.2 Overview of Server Hardware, Network, and Operating System

Oracle Clusterware must be installed successfully as part of an Oracle Grid Infrastructure for a cluster installation before attempting to install Oracle RAC. If you plan to install Oracle RAC for an Oracle Flex Cluster, then you must have installed Oracle Clusterware using the Oracle Flex Cluster option.

To complete installations successfully, ensure that required hardware, network, and operating system preinstallation steps for Oracle software are performed as required. Failure to complete the required preinstallation steps is the most common reason for unsuccessful installations.

Before Oracle Clusterware is installed as part of an Oracle Grid Infrastructure for a cluster installation, you must have completed installing and configuring CPUs, memory, shared storage, local disks, network cards, host bus adapters, interconnects, and any other networking or server hardware. You should also have installed the operating system, and any required packages or third-party software. Review your vendor documentation to complete these tasks, and if relevant, work with your vendor to complete the Oracle preinstallation steps that are listed in this document to confirm that the vendor hardware and software is correctly configured.

Server and network preparation for installation includes the following:

1.2.1 Review Server Hardware and Software Requirements

The following summary of server hardware and software configuration requirements and recommendations will enable you to prepare for a successful installation of Oracle RAC. Cluster Node Member Requirements for Oracle RAC

Each node in a cluster requires the following:

  • Supported server hardware, including processors and system configuration.

    Review My Oracle Support before starting an installation on your current hardware and before purchasing new hardware to ensure that the hardware is supported by Oracle Clusterware with Oracle RAC 12c Release 1 (12.1).

    Also review the preinstallation chapters in Oracle Grid Infrastructure Installation Guide for more details about the supported configurations.


    You must use the same operating system on each node in the cluster. Oracle strongly recommends that you use the same software configurations on each node of the cluster. Oracle Clusterware and Oracle RAC do not support heterogeneous platforms (each server must run the same Oracle software binaries) in the same cluster.
  • Operating system updates listed in the system requirements.

    For some operating systems, Oracle may require updates, such as service packs and individual patches. If such requirements exist, then they are stated in the Release Notes for a particular release. Refer to your operating system vendor for required operating system updates.

  • Network connections required for the node type you are configuring (Hub Node or Leaf Node). Recommended for Oracle RAC: System Administrator Tasks

Oracle recommends the following tasks to simplify server installation and maintenance, and to prevent service issues:

  • Using a time protocol, such as Network Time Protocol (NTP), to ensure that all nodes in the cluster use the same reference time. With Oracle Clusterware 12c Release 1 (12.1), if NTP servers are not provided during Oracle Grid Infrastructure installation, then the Oracle Clusterware installation enables the Cluster Time Synchronization Service (CTSS).

  • Configuring redundant switches, for all cluster sizes.

  • Using identical server hardware on each node, to simplify server maintenance.

  • Avoiding resource contention issues by not installing Oracle RAC on a primary domain controller or backup domain controller. Additional Options: System Administrators and Vendors

After you have set up server hardware, review "Checking the Hardware Requirements" in Oracle Grid Infrastructure Installation Guide for your platform to ensure that your system has enough RAM, that the TEMP environment variable points to a location that has enough available space for the installation, and that your system meets other hardware requirements.

1.2.2 Overview of Server Environment Configuration

Configure the users and user environments as described in the preinstallation chapters of Oracle Grid Infrastructure Installation Guide. These include the following tasks:

  • Creating operating system users to install Oracle software

  • Configuring the Oracle software owner user environments

1.2.3 Overview of Oracle Base and Oracle Home Directories

The Oracle base directory is the location where Oracle configuration files installed by a particular Oracle installation owner are stored. An Oracle base directory can be used for multiple installations of software by a given installation owner.

The Oracle base and Oracle home directory structures are different for Oracle Database and Oracle Grid Infrastructure for a cluster. By default, the Oracle Database software binary files are installed by version and Oracle home name in a subdirectory of the Oracle base directory. Every Oracle home can have its own Oracle base. The Oracle Grid Infrastructure for a cluster software binaries are stored in an Oracle home (the Grid home) that is outside of the Grid Infrastructure installation owner Oracle base. There can be only one active Grid home on each cluster member, or only one active shared home, and it must not be under the Oracle base for the Grid Infrastructure installation owner.

Typically, the Oracle base path is based on the installation owner name. If you have separate installation owners for the Oracle Grid Infrastructure installation and the Oracle RAC installation, then you have two Oracle base paths that are in accordance with Optimal Flexible Architecture (OFA) guidelines. For example, if the user grid is the installation owner of the Oracle Grid infrastructure installation and the user oracle is the installation owner of the Oracle Database installation, then you have two Oracle base directories:

  • u01/app/grid: This is the Oracle base for the Grid installation owner (grid), which owns the Oracle Grid Infrastructure binaries

  • u01/app/oracle: This is the Oracle base for the Oracle Database installation owner (oracle), which owns the Oracle Database binaries

In addition, you have a Grid home that is in a different path than the Oracle base path for the Grid installation owner, and the Oracle base path for the Oracle Database owner:


The Grid home path is outside of the Oracle base directory for both the Oracle Database installation owner (oracle) and the Oracle Grid Infrastructure owner (grid). The path to the Grid home (/u01 and /u01/app) is owned by root after installation, so the Oracle base for installation owners should be created by system administrators, and given read, write and execute permissions to the Oracle installation owner that is permitted to write to that Oracle base.

Oracle recommends that you do not set an Oracle home environment variable, and instead enable OUI to create it. If the Oracle base path is /u01/app/oracle, then by default, OUI creates the following Oracle home path:


The variable n is the Oracle home number. The first time you create an Oracle home as the oracle user, the default Oracle home location is the following:


Ensure that the paths that you select for Oracle software, such as Oracle home paths and the Oracle base path, use only ASCII characters. Because installation user names are used by default for some paths, this ASCII character restriction applies to user names, file names, and directory names.

1.2.4 Overview of Network and Internet Configuration

You must configure each server so it can communicate with the other nodes in the cluster. Also, you should configure one or more nodes to access the Internet and support a web browser. Overview of Network Interface Configuration

During the installation of Oracle Grid Infrastructure for a cluster, identify the planned use for global interface for each node, and provide the interface information required for the type of node (Hub Node or Leaf Node) that you are configuring.

Identify each interface as one of the following:

  • A Public interface type (used with public IP addresses and virtual IP addresses)

  • A Private interface type (used with the networks for the interconnect between cluster member nodes)

  • An ASM interface type (used for communication with Oracle ASM instances on other nodes)

  • An ASM and Private interface type (used for both interconnects between cluster member nodes and communication with Oracle Flex ASM instances on other nodes)

  • A Do not use interface type, which Oracle Clusterware and Oracle RAC ignores

For example, an interface used as a dedicated interface for a network file system such as NFS should be marked as a Do not use interface type.

You configure the network during the Oracle Grid Infrastructure installation; you do not perform additional network configuration during an Oracle RAC installation.

See Also:

Oracle Grid Infrastructure Installation Guide for detailed information about network requirements Overview of Browser Requirements

Web browsers are required to use Oracle Enterprise Manager Database Express and Oracle Enterprise Manager Cloud Control. Web browsers must support JavaScript, and the HTML 4.0 and CSS 1.0 standards. For a list of browsers that meet these requirements, see the Oracle Enterprise Manager certification matrix on My Oracle Support:

See Also:

1.2.5 Overview of Platform-Specific Server Configuration

Oracle Clusterware and Oracle RAC are tested with specific operating system versions, and specific operating system components. Oracle requires that you use the operating system versions and components that are certified for this release.

Oracle recommends that you or your system administrator review the system requirements carefully in Oracle Grid Infrastructure Installation Guide before beginning installation, to ensure that your system meets these requirements. If your system does not meet minimum hardware, operating system version, and component requirements, then your installation may fail to complete, or other errors may develop during Oracle Clusterware or Oracle Database run time.

In addition to the standard system requirements configuration, deployment on specific server hardware can include additional operating system configuration steps. Review the preinstallation chapter in Oracle Grid Infrastructure Installation Guide, and check the My Oracle Support Certify page to ensure that you are aware of any additional requirements or recommendations for your specific hardware and platform configuration.

1.3 Overview of Oracle RAC Storage

For both the Enterprise and Standard Editions of Oracle RAC, the hard disk requirements for Oracle Database components include 32 MB required to install Java Runtime Environment (JRE) and OUI on the disk partition where the operating system is installed. If sufficient space is not detected, then the installation fails and an error message appears.

To install Oracle RAC, you must configure shared storage for the database files and optionally the recovery files. The database fast recovery area must be located on shared storage.

See Oracle Grid Infrastructure Installation Guide to review storage options for installation planning. Storage and system administrators can see this chapter to configure storage for database files for an Oracle RAC database.

See Also:

Oracle Database Administrator's Guide for information about recovery areas

1.3.1 About Oracle RAC Storage and Oracle ACFS

Oracle Automatic Storage Management Cluster File System (Oracle ACFS) is a multiplatform, scalable file system, and storage management technology that extends Oracle ASM functionality to support customer files maintained outside of the Oracle Database. Files supported by Oracle ACFS include database and application executable files, trace files, alert logs, application reports, PFILEs, and configuration files. About the Oracle ASM Dynamic Volume Manager

The Oracle ASM Dynamic Volume Manager (Oracle ADVM) provides volume management services for disks and a standard disk device driver interface to clients (users and applications). File systems and other disk-based applications issue I/O requests to Oracle ADVM volume devices as they would to other storage devices on a vendor operating system. Oracle ADVM extends Oracle ASM by providing a disk driver interface to Oracle ASM storage allocated as Oracle ASM volume files. You can use Oracle ADVM to create virtual disks that contain file systems. These file systems contained on Oracle ASM volumes can support files beyond Oracle database files, such as executable files, report files, trace files, alert logs, and other application data files.

1.3.2 General Storage Considerations for Oracle RAC

For all installations, you must choose the storage option to use for Oracle RAC database files. You do not have to use the same storage option for each file type.

Use the following guidelines when choosing the storage options to use for each file type. You can choose any combination of the supported shared storage options for each file type if you satisfy all requirements listed for the chosen storage options

  • Oracle recommends that you choose Oracle ASM as the shared storage option for database and recovery files. You do not have to have an Oracle ASM instance running on every hub node in a Big Cluster configuration, but every hub node must have direct access to the shared storage.

  • For Standard Edition Oracle RAC installations, Oracle ASM is the only supported shared storage option for database or recovery files.

  • If you do not have a storage option that provides external file redundancy, then you must configure at least three voting disk areas to provide voting disk redundancy.

  • If you intend to use Oracle ASM with Oracle RAC and you did not use Oracle ASM for the Oracle Clusterware files (Oracle Cluster Registry (OCR) and voting disk), then you must configure one or more Oracle ASM instances with Oracle ASM Configuration Assistant (ASMCA) before starting OUI. Oracle ASM runs on one ore more hub nodes in the cluster.

  • If you intend to upgrade an existing Oracle RAC database, then you must ensure that your system meets the following conditions:

    • OUI and DBCA are run on the node where the Oracle RAC database instance is located.

    • The Oracle RAC database instance is running on the same nodes that you intend to make members of the new cluster installation. For example, if you have an existing Oracle RAC database running on a three-node cluster, then you must install the upgrade on all three nodes. You cannot upgrade only two nodes of the cluster, removing the third instance in the upgrade.

    See Also:

    Oracle Database Upgrade Guide for information about how to prepare for upgrading an existing database

1.3.3 Overview of Oracle Database and Recovery File Options

There are two ways of storing Oracle Database and recovery files:


When creating a new Oracle RAC database using OUI, storing data files and recovery files on raw devices (unformatted partitions) is not supported. Place data files and recovery files on a shared file system or on Oracle ASM. If you are upgrading a database that uses raw devices, then they are still supported with Oracle Database 11g Release 2.
  • Oracle Automatic Storage Management: Oracle ASM is an integrated, high-performance database file system and disk manager for Oracle Database files. It performs striping and mirroring of database files automatically.


    For Standard Edition Oracle Database installations using Oracle RAC, Oracle ASM is the only supported storage option.
  • A supported shared file system: Supported file systems include the following:

    • Direct Network File Systems Client (Direct NFS Client): You can configure Oracle Database to access NFS servers directly using Direct NFS Client. Direct NFS Client supports using NFSv3, NFSv4 and NFSv4.1 (excluding Parallel NFS) to access the NFS server. Direct NFS Client is an optimized NFS client that provides faster and more scalable access to NFS storage located on NAS storage devices (accessible over TCP/IP). Direct NFS Client is built directly into the database kernel and provides faster performance than what can be provided by the operating system's NFS driver. When accessing NFS servers, Oracle Database bypasses the operating system and generates exactly the requests it needs (no user configuration or tuning required).

Table 1-1 shows the storage options supported for storing Oracle Database files and Oracle Database recovery files. Oracle Database files include data files, control files, redo log files, the server parameter file (SPFILE), and the password file.

Table 1-1 Supported Storage Options for Oracle Database and Recovery Files

Storage Option File Types Supported
Database Recovery

Oracle ASM



Oracle ASM Cluster File System (Oracle ACFS)



Direct NFS Client



Local storage



Shared unformatted partitions



1.4 Additional Information to Prepare for Installation

This section contains additional information about Oracle Clusterware, Oracle Automatic Storage Management (Oracle ASM), and Oracle RAC, that may be helpful for your installation plan team to read to decide how to configure your installation. It contains the following topics:

1.4.1 Oracle ASM is Installed with Oracle Grid Infrastructure

In past releases, Oracle ASM was installed as part of the Oracle Database installation. With Oracle Database 11g Release 2 (11.2) and later releases, Oracle ASM is part of an Oracle Grid Infrastructure installation. To upgrade an existing Oracle ASM installation, you must upgrade Oracle ASM by running an Oracle Grid Infrastructure upgrade.

If you did not select Oracle ASM as the storage option for the Oracle Clusterware files, then you must first use Oracle ASM Configuration Assistant (ASMCA) on one of the Hub Nodes to configure Oracle ASM, create an Oracle ASM instance, and create a disk group to use for your Oracle Database storage.

1.4.2 Hub Nodes and Shared Components of Oracle RAC Installations

For Oracle RAC, you and your system administrator should note that all Hub Node instances in Oracle RAC environments share the control file, server parameter file, redo log files, and all data files. These files must be placed on Oracle ASM, and all the cluster database instances on the Hub Node must have access to these files. Each instance also has its own set of redo log files. During failures, shared access to redo log files enables surviving instances to perform recovery.

See Also:

Oracle Automatic Storage Management Administrator's Guide for more information about Hub Nodes

1.4.3 Simplified Upgrade of TIMESTAMP WITH TIME ZONE Data

As part of an installation of Oracle Database 12c Release 1 (12.1), time zone version files from 1 to 12 are installed in the path $ORACLE_HOME/oracore/zoneinfo/. You can continue to use the current time zone version or upgrade to the latest version. Oracle recommends that you upgrade the server to the latest time zone version. Upgrading to a new time zone version may cause existing TIMESTAMP WITH TIME ZONE (TSTZ) data to become stale. Using the newly provided DBMS_DST PL/SQL packages, you can update the TSTZ data transparently with minimal manual procedures and system downtime.

All instances of an Oracle RAC database must use the same time zone. The Oracle RAC database time zone defaults to the time zone setting of the Oracle Grid Infrastructure Grid user, except when an instance is started with SQL*Plus. When you use SQL*Plus, you must be sure to use the same time zone setting for the database instance that is used for Oracle Clusterware. You can change the time zone Oracle Clusterware uses for a database by using the following command, where time_zone is the time zone to which you want to change:

srvctl setenv database -env 'TZ=time_zone'

Time zone version files are also installed on the clients. Starting with Oracle Database 11g Release 2, you no longer need to upgrade Client time zone files immediately. Upgrades can be done at a time when it is most convenient to the system administrator. However, there could be a small performance penalty when client and server use different time zone versions.

See Also:

1.4.4 Ensure an External Jobs User Is Created for HP-UX

If you are installing Oracle RAC on HP-UX, then ensure that there is a low-privileged user created to own external jobs. Be aware that you must set this user as the external jobs user by logging in as the root user and modifying $ORACLE_HOME/rdbms/admin/externaljob.ora after installation. Only the root user can modify this file.

1.4.5 Oracle Database 12c Real Application Clusters Release Compatibility

You can install and operate different releases of Oracle Database software on the same computer:

  • If you have Oracle Clusterware installed and different releases of other Oracle software installed, then the Oracle Clusterware release must be later than or equal to the Oracle Database software release. Oracle Clusterware and Oracle ASM are both upgraded to 12c Release 1 (12.1) when you perform an Oracle Grid Infrastructure 12c Release 1 (12.1) installation

  • If you have an existing Oracle home, then you can create a new Oracle home and install Oracle Database 12c Release 1 (12.1) into the new Oracle home. You should ensure that Oracle Clusterware is in a separate Oracle Grid Infrastructure home. Oracle Grid Infrastructure for a Cluster installations cannot be installed in the Oracle base directory for Oracle Database.

  • If you are running Oracle Database 9i Release 2 Oracle RAC, and you want to continue to use that release, then you must run cluster software that is compatible with that release, such as Oracle Cluster Manager or a third party cluster software.


    To remove third party cluster software after upgrading your database, you must first remove the third party cluster software, and then re-install Oracle Clusterware.
  • If OUI detects a previous database release, then OUI asks you about your upgrade preferences. You have the option to upgrade one of the previous release databases with DBUA or to create a database using DBCA. The information collected during this dialog is passed to DBUA or DBCA after the software is installed.

    If OUI detects a previous Oracle Clusterware release, then you are asked to upgrade the existing Oracle Clusterware installation. Only one Oracle Clusterware version can be active on a server, and a server must be a member of only one cluster.


    Do not move Oracle executable files from the directory in which they were installed to another location. Doing so can cause dynamic link failures. To move the executable files to a new location, you must reinstall the software.
  • You cannot install Oracle Grid Infrastructure for a standalone server (Oracle Restart) and then install Oracle Grid Infrastructure for a cluster. If you have Oracle Restart installed, then you must remove that installation before you can install Oracle Grid Infrastructure for a cluster.

  • You can run different releases of Oracle Database and Oracle ASM. For example, you can use Oracle ASM 12c Release 1 (12.1) with an Oracle Database 11g Release 2 (11.2) database. However, you can only run an Oracle Database version of a release before Oracle Grid Infrastructure 12c on a Hub Node. You cannot run earlier releases on a Leaf Node.


    When using different Oracle ASM and Oracle Database releases, the functionality of each depends on the functionality of the earlier software release. For example, an Oracle Database 11g Release 11.2 database using an Oracle ASM 12c Release 1 (12.1) instance is not able to use new features available for Oracle ASM 12c Release 1 (12.1), but instead it can use only Oracle ASM 11.2 features.

1.5 Confirming Cluster Readiness for Oracle RAC Installation with CVU

Before you start your installation, use Cluster Verification Utility (CVU) to ensure that your system is prepared for Oracle RAC installation. If any checks fail, then fix the errors reported, either manually or by using a generated fixup script, or contact your system or storage administrator to have the cause of the errors addressed.

CVU is available in the Grid home, in the bin directory. For example, if the Oracle Grid Infrastructure for a cluster home is /u01/app/12.1.0/grid, then the path is /u01/app/12.1.0/grid/bin. To start CVU, navigate to the Grid home bin directory, and use a command similar to the following:

cluvfy stage -pre dbinst -fixup -n nodelist -r release -osdba OSDBA -verbose

In the preceding command syntax, nodelist is a comma-delimited list of node names and release is the version of the Oracle Database software being installed. The -fixup, -osdba, and -verbose flags are optional.

For example, for a two-node cluster with nodeA and nodeB, where you are testing the cluster to prepare to install Oracle Database 12c with Oracle RAC, and your OSDBA group is dba, the following command checks for system readiness:

$ ./cluvfy stage -pre dbinst -fixup -n nodea,nodeb -osdba dba -verbose

For more information about CVU commands, enter ./cluvfy -help.

See Also:

Oracle Clusterware Administration and Deployment Guide for detailed information about CVU

1.6 Installing Oracle Database 12c on Systems with Existing Databases

If you are planning an installation on a system where you have an existing Oracle RAC or Oracle Database installation, then you must perform additional tasks to prepare your system for installation.

Table 1-2 provides an overview of what you must do if you have an existing Oracle Database installation. Review the table, and perform tasks as required.

See Also:

Oracle Database Upgrade Guide for additional information about preparing for and performing upgrades

Table 1-2 Overview of System Preparation for Upgrades or Coexisting Databases

Installation Scenario What you must do

Upgrading from Oracle Database 10g Release 1 (10.1) to 12c Release 1 (12.1)

No additional tasks. Refer to About Oracle Database 10g Listener Migration

Installing Oracle Database 12c Release 1 (12.1) on a system to coexist with Oracle Database 10g Release 1 (10.1)

No additional tasks. Refer to About Oracle Database 10g Listener Migration

1.7 About Oracle Database 10g Listener Migration

If your system has an Oracle Database 10g installation, and you install Oracle Database 12c Release 1 (12.1) either to coexist with or to upgrade the Oracle Database 10g installation, then most installation types configure and start a default Oracle Net listener using TCP/IP port 1521 and the IPC key value EXTPROC. One of the following occurs:

  • During a coexisting installation, Database Configuration Assistant (DBCA) automatically migrates the listener and related files from the Oracle Database 10g Oracle home to the Oracle Database 11g Oracle home.

  • During an upgrade, Oracle Database Upgrade Assistant (DBUA) automatically locates the existing Oracle Database 10g listener, and migrates the listener to Oracle Database 12c Release 1 (12.1).


    For Oracle Database 12c Release 1 (12.1) to coexist with Oracle Database 10g Release 1 (10.1) databases using Oracle ASM, the database must be Oracle Database 10g Release or later.