3 Configuring Operating Systems for Oracle Grid Infrastructure and Oracle RAC

Complete operating system configuration requirements and checks before you start the Oracle Grid Infrastructure installation.

3.1 Reviewing Operating System and Software Upgrade Best Practices

Review the general planning guidelines and platform-specific information about upgrades and migration.

3.1.1 General Upgrade Best Practices

Review these best practices before upgrading a current installation of Oracle Grid Infrastructure.

If you have an existing Oracle installation, then do the following:

  • Record the release numbers, patches, and other configuration information

  • Review upgrade procedures for your existing installation

  • Review Oracle upgrade documentation before proceeding with installation, to decide how you want to proceed


Always create a backup of existing databases before starting any configuration change.

To find the most recent software updates, and to find best practices recommendations about preupgrade, postupgrade, compatibility, and interoperability, see Oracle 12c Upgrade Companion (My Oracle Support Note 1462240.1):


3.1.2 Oracle ASM Upgrade Notifications

Be aware of these issues regarding Oracle ASM upgrades.

  • You can upgrade Oracle Automatic Storage Management (Oracle ASM) 11g release 1 (11.1) and later without shutting down an Oracle RAC database by performing a rolling upgrade either of individual nodes, or of a set of nodes in the cluster. However, if you have a standalone database on a cluster that uses Oracle ASM, then you must shut down the standalone database before upgrading. If you are upgrading from Oracle ASM 10g, then you must shut down the entire Oracle ASM cluster to perform the upgrade.

  • The location of the Oracle ASM home changed in Oracle Grid Infrastructure 11g release 2 (11.2) so that Oracle ASM is installed with Oracle Clusterware in the Oracle Grid Infrastructure home (Grid home).

    If you have an existing Oracle ASM home from a earlier release, then you may want to consider other configuration changes to simplify or customize storage administration.

  • When upgrading from Oracle Grid Infrastructure 11g release 2 (11.2) or Oracle Grid Infrastructure 12c release 1 (12.1) to a later release, if there is an outage during the rolling upgrade, then when you restart the upgrade, ensure that you start the earlier release of Oracle Grid Infrastructure. You must then bring the Oracle ASM cluster back in the rolling migration mode, because two nodes of different releases cannot run in the cluster.

  • You must be an Administrator user to upgrade Oracle ASM.

3.1.3 Rolling Upgrade Procedure Notifications

Be aware of this information regarding rolling upgrades.

  • During rolling upgrades of the operating system, Oracle supports using different operating system binaries when both versions of the operating system are certified with the Oracle Database release you are using.

  • Using mixed operating system versions is supported during upgrade only.

    Be aware that mixed operating systems are supported only for the duration of an upgrade, over the period of a few hours.

  • Oracle Clusterware does not support nodes that have processors with different instruction set architectures (ISAs) in the same cluster. Each node must be binary compatible with the other nodes in the cluster.

    For example, you cannot have one node using an Intel 64 processor and another node using an IA-64 (Itanium) processor in the same cluster. You could have one node using an Intel 64 processor and another node using an AMD64 processor in the same cluster because the processors use the same x86-64 ISA and run the same binary release of Oracle software.


Your cluster can have nodes with processors of different manufacturers, speeds, or sizes, but this is not recommended.

3.2 Reviewing Operating System Security Common Practices

Secure operating systems are an important basis for general system security.

  • Ensure that your operating system deployment is in compliance with common security practices as described in your operating system vendor security guide.

3.3 Logging In To a Remote Windows Server

During installation, you are required to perform tasks as an Administrator user on the cluster nodes.

Configure remote access for the user accounts that you want to enable for remote display.

3.3.1 Windows Telnet Services Support

Ensure that the Telnet service is installed and started.

Microsoft changed the name from Terminal Services to Remote Desktop Services with the release of Windows Server 2008 R2. Microsoft also introduced the Remote Desktop Connections client, which can be used to connect to a Windows server that has Terminal Services installed.

3.3.2 Configuring Remote Desktop Services and Remote Desktop Connections

On Windows, Oracle supports installing, configuring, and running Oracle Database software through Remote Desktop Services (formerly known as Terminal Services).

If you do not use Terminal Services in console mode, then you might encounter problems with configuration assistants after the installation or with starting Oracle Clusterware components after installation.

See Also: Configuring Remote Desktop Connections with Windows Server 2008 or Windows Server 2008 R2

Due to changes in Windows 2008 and Windows Server 2008 R2, you no longer need to connect to session 0 for installation.

  • Use the Remote Desktop Connection client, but do not specify the /console switch, as shown in the following example:
    mstsc /v:servername /f

3.4 Checking Hardware and Software Certification on My Oracle Support

The My Oracle Support website also provides compatible client and database releases, patches, and workaround information for bugs.

The hardware and software requirements included in this installation guide were current at the time this guide was published. However, because new platforms and operating system software versions might be certified after this guide is published, review the certification matrix on the My Oracle Support website for the most up-to-date list of certified hardware platforms and operating system versions.

  • View certification information on both Oracle Technology Network (OTN) and My Oracle Support.
    The OTN certification page can be found on the following website: http://www.oracle.com/technetwork/database/options/clustering/overview/index.html
  • View hardware certification details for Microsoft Windows platforms on Oracle Technology Network, at the following URL:
  • View My Oracle Support for guidance about supported hardware options that can assist you with your purchasing decisions and installation planning.

    The My Oracle Support certifications page contains more detailed information about certified hardware and has information specific to each release and platform. My Oracle Support is available at the following URL:


    You must register online before using My Oracle Support. Use the steps described in the support document "Locate Oracle Database Server Certification Information for Microsoft Windows Platforms (Doc ID 1062972.1)" to locate the certification information for your Windows operating system.


    Contact your Oracle sales representative if you do not have a My Oracle Support account.

3.5 Identifying Software Requirements

Depending on the products that you intend to install, verify that the required operating system software is installed on each node of your cluster.

Requirements listed in this document are current as of the date listed on the title page. To obtain the most current information about operating system requirements, see the online version in the Oracle Help Center at the following URL:


OUI performs checks on your system to verify that it meets the listed operating system requirements. To ensure that these checks complete successfully, verify the requirements before you start OUI.


Oracle does not support running different operating system versions on cluster members, unless an operating system is being upgraded. You cannot run different operating system version binaries on members of the same cluster, even if each operating system is supported.

Table 3-1 Oracle Grid Software Requirements for Windows Systems

Requirement Value

System Architecture

Processor: AMD64, or Intel Extended memory (EM64T)


Oracle provides only x64 releases of Oracle Database with Oracle RAC for Windows.

The x64 release of Oracle RAC runs on the x64 version of Windows on AMD64 and EM64T hardware. For additional information, visit My Oracle Support, as described in "Checking Hardware and Software Certification on My Oracle Support".

Operating system

Oracle Grid Infrastructure and Oracle RAC for x64 Windows:

  • Windows Server 2008 x64 with service pack 2 (SP2) - Standard, Enterprise, DataCenter, and Web editions.

  • Windows Server 2008 R2 x64 - Foundation, Standard, Enterprise, DataCenter, and Web editions.

  • Windows Server 2012 x64 - Standard, Datacenter, Essentials, and Foundation editions

  • Windows Server 2012 R2 x64 - Standard, Datacenter, Essentials, and Foundation editions

The Windows Multilingual User Interface Pack is supported. The Server Core option is not supported.


Oracle Clusterware, Oracle ASM and Oracle RAC 12c Release 1 (12.1) are not supported on x86 (32-bit) Windows operating systems.


The following components are supported with the Microsoft Visual C++ 2010 SP1, Microsoft Visual C++ 2012, Microsoft Visual C++ 2013 Update 2, and Intel 12.1 C compilers:

  • Oracle Call Interface (OCI)

  • Pro*C/C++ (not supported with Microsoft Visual C++ 2013 Update 2 at this time of release.)

  • External callouts

  • Oracle XML Developer's Kit (XDK)

Oracle C++ Call Interface is supported with:

  • Microsoft Visual C++ 2010 SP1

  • Microsoft Visual C++ 2012 - OCCI libraries are installed under ORACLE_HOME\oci\lib\msvc\vc11. When developing OCCI applications with MSVC++ 2012, ensure that the OCCI libraries are correctly selected from this directory for linking and executing.

  • Microsoft Visual C++ 2013 - OCCI libraries are installed under ORACLE_HOME\oci\lib\msvc\vc12. When developing OCCI applications with MSVC++ 2013, ensure that the OCCI libraries are correctly selected from this directory for linking and executing.

  • Intel 12.1 C compilers with Microsoft Visual Studio 2010 STLs

If you are currently running an operating system version that is not supported by Oracle Database 12c Release 1 (12.1), such as Windows Server 2003 x86, then see Oracle Database Platform Guide for Microsoft Windows for upgrade instructions.


The platform-specific hardware and software requirements included in this guide were current when this guide was published. However, because new platforms and operating system software versions might be certified after this guide is published, review the certification matrix on the My Oracle Support website for the most up-to-date list of certified hardware platforms and operating system versions:


3.5.1 Windows Firewall Feature on Windows Servers

When installing Oracle Grid Infrastructure software or Oracle RAC software on Windows servers, it is mandatory to disable the Windows Firewall feature.

If the Windows Firewall is enabled, then remote copy and configuration assistants such as virtual IP configuration assistant (VIPCA), Network Configuration Assistant (NETCA), and Oracle Database Configuration Assistant (DBCA) will fail during Oracle RAC installation. Thus, you must disable the firewall on all the nodes of a cluster before performing an Oracle RAC installation.


The Windows Firewall should never be enabled on a NIC that is used as a cluster interconnect (private network interface) or for accessing an Oracle ASM network.

After the installation is successful, you can enable the Windows Firewall for the public connections. However, to ensure correct operation of the Oracle software, you must add certain executables and ports to the Firewall exception list on all the nodes of a cluster.

Additionally, the Windows Firewall must be disabled on all the nodes in the cluster before performing any clusterwide configuration changes, such as:

  • Adding a node

  • Deleting a node

  • Upgrading to patch release

  • Applying a patch bundle or an emergency patch

If you do not disable the Windows Firewall before performing these actions, then the changes might not be propagated correctly to all the nodes of the cluster.

3.6 Oracle Enterprise Manager Requirements

Verify that your installed Oracle Enterprise Manager meets the minimum requirements for use with Oracle Grid Infrastructure.

All Oracle Enterprise Manager products that you use on your system must be of the same release. Oracle Database 12c Release 1 (12.1) does not support releases of Enterprise Manager earlier than Oracle Enterprise Manager Cloud Control 12c.

See Also:

Oracle Enterprise Manager Cloud Control Basic Installation Guide available on the Enterprise Manager Cloud Control installation media

3.7 Installation Requirements for Web Browsers

Web browsers are required to use Oracle Enterprise Manager Database Express and Oracle Enterprise Manager Cloud Control.

Web browsers must support Java Script, 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: https://support.oracle.com

3.8 Configuring Time Synchronization for the Cluster

Oracle Clusterware requires the same time zone setting on all cluster nodes.

3.8.1 About Cluster Time Synchronization

For the Microsoft Windows operating system, there are three different methods you can use to synchronize the time between the nodes of your cluster.

During installation, the installation process picks up the time zone environment variable setting of the Oracle Installation user for Oracle Grid Infrastructure on the node where OUI runs. Then the installation process uses that time zone value on all nodes as the default TZ environment variable setting for all processes managed by Oracle Clusterware. The time zone default is used for databases, Oracle ASM, and any other managed processes.

You have three options for time synchronization between cluster nodes:

  • Windows Time service

  • An operating system configured network time protocol (NTP)

  • Oracle Cluster Time Synchronization Service

Oracle Cluster Time Synchronization Service is designed for organizations whose cluster servers are unable to access NTP services. If you use NTP, then the Oracle Cluster Time Synchronization daemon (ctssd) starts in observer mode. If neither NTP or the Windows Time service is found, then ctssd starts in active mode and synchronizes time among cluster members without contacting an external time server.


  • Before starting the installation of Oracle Grid Infrastructure, Oracle recommends that you ensure the clocks on all nodes are set to the same time.

  • The IP address for an NTP server can be an IPv6 address.

3.8.2 Configuring the Windows Time Service

The Windows Time service (W32Time) provides network clock synchronization on computers running Microsoft Windows.

If you are using Windows Time service, and you prefer to continue using it instead of Cluster Time Synchronization Service, then you must modify the Windows Time service settings to jumps in time and allow the time to gradually match with the reference time. Restart the Windows Time service after you complete this task.
  1. To configure Windows Time service, use the following command on each node:
    C:\> W32tm /register
  2. To modify the Windows Time service to work in an Oracle RAC environment, perform the following steps:
    1. Open the Registry Editor (regedit)
    2. Locate the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\W32Time\Config key.
    3. Set the following Windows Time service parameters to these decimal values:
      • MaxPosPhaseCorrection to 600

      • MaxNegPhaseCorrection to 600

      • MaxAllowedPhaseOffset to 600

      These parameter settings specify that small time adjustments are allowed when the time difference between the reference and cluster nodes is under 10 minutes.


    You should configure the Windows Time service to meet the requirements of your environment, with assistance from Microsoft, if necessary. The recommended settings provided for the three parameters are the settings that Oracle recommends to allow time adjustments to happen through slewing (gradually adjusting the clock using small changes) rather than in large steps (setting the clock to a new time). Large time adjustments in a single step are not supported.
  3. To put the changes into effect, use the following command:
    C:\> W32tm /config /update

See Also:

For more information about using and configuring the Windows Time Service, see:
  • Microsoft® Support article ID 816042: "How to configure an authoritative time server in Windows Server"

  • Microsoft® Support article ID 939322: "Support boundary to configure the Windows Time service for high accuracy environments"

  • "The NTP FAQ and HOWTO" at http://www.ntp.org/ntpfaq/

3.8.3 Configuring Network Time Protocol

The Network Time Protocol (NTP) is a client/server application.

Each server must have NTP client software installed and configured to synchronize its clock to the network time server. The Windows Time service is not an exact implementation of the NTP, but it based on the NTP specifications.

If you decide to use NTP instead of the Windows Time service, then, after you have installed the NTP client software on each cluster node, you must start the NTP service with the -x option to prevent time from being adjusted backward. Restart the network time protocol service after you complete this task.

  1. Use the registry editor to edit the value for the ntpd executable under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\NTP
  2. Add the -x option to the ImagePath key value, behind %INSTALLDIR%\ntpd.exe.
  3. Restart the NTP service using the following commands:
    net stop NTP
    net start NTP

3.8.4 Configuring Cluster Time Synchronization Service

Cluster Time Synchronization Service (CTSS) is provided by Oracle to synchronize the time across the nodes in your cluster.

When OUI discovers that neither the Windows Time or NTP services are active, the Cluster Time Synchronization Service is installed in active mode and synchronizes the time across the nodes. If the Windows Time service or NTP service is found on the server, then the Cluster Time Synchronization Service is started in observer mode, and no active time synchronization is performed by the Cluster Time Synchronization Service within the cluster.
To use Cluster Time Synchronization Service to provide synchronization service in the cluster, disable the Windows Time service and stop the NTP service. If you have an NTP service on your server but you cannot use the service to synchronize time with a time server, then you must deactivate and deinstall the NTP to use Cluster Time Synchronization Service.
  • To confirm that the Cluster Time Synchronization Service is active after installation, enter the following command as the Oracle Grid Infrastructure installation owner:
    crsctl check ctss