2 Configuring Servers for Oracle Grid Infrastructure and Oracle RAC

This chapter describes the operating system tasks you must complete on your servers before you install Oracle Grid Infrastructure for a cluster and Oracle Real Application Clusters (Oracle RAC). The values provided in this chapter are installation minimum only. Oracle recommends that you configure production systems in accordance with planned system loads.

This chapter contains the following topics:

2.1 Checking Server Hardware and Memory Configuration

Run the following commands to gather your current system information:

  1. To determine the physical RAM size, enter the following command:

    # grep MemTotal /proc/meminfo
    

    If the size of the physical RAM installed in the system is less than the required size, then you must install more memory before continuing.

  2. To determine the size of the configured swap space, enter the following command:

    # grep SwapTotal /proc/meminfo
    

    If necessary, see your operating system documentation for information about how to configure additional swap space.

  3. To determine the amount of space available in the /tmp directory, enter the following command:

    # df -h /tmp
    
  4. To determine the amount of free RAM and disk swap space on the system, enter the following command:

    # free
    
  5. To determine if the system architecture can run the software, enter the following command:

    # uname -m
    

    Verify that the processor architecture matches the Oracle software release to install. For example, you should see the following for a x86-64 bit system:

    x86_64
    

    If you do not see the expected output, then you cannot install the software on this system.

  6. Verify that shared memory (/dev/shm) is mounted properly with sufficient size using the following command:

    df -h /dev/shm
    

    The df-h command displays the filesystem on which /dev/shm is mounted, and also displays in GB the total size and free size of shared memory. See Section 2.4, "Server Memory Minimum Requirements" for more information about shared memory planning.

2.2 General Server Minimum Requirements

  • Select servers with the same instruction set architecture; running 32-bit and 64-bit Oracle software versions in the same cluster stack is not supported.

  • Ensure that the server is started with runlevel 3 or 5.

  • Ensure display cards provide at least 1024 x 768 display resolution, so that OUI displays correctly while performing a system console-based installation.

  • Ensure servers run the same operating system binary.

  • Oracle Grid Infrastructure installations and Oracle Real Application Clusters (Oracle RAC) support servers with different hardware in the same cluster. Your cluster can have nodes with CPUs of different speeds or sizes, but Oracle recommends that you use nodes with the same hardware configuration.

    Oracle recommends that if you configure clusters using different configuration, that you categorize cluster nodes into homogenous pools as part of your server categorization management policy.

    See Also:

    Oracle Clusterware Administration and Deployment Guide for more information about server state and configuration attributes, and about using server pools to manage resources and workloads

2.3 Server Storage Minimum Requirements

Each system must meet the following minimum storage requirements:

  • 1 GB of space in the /tmp directory.

    If the free space available in the /tmp directory is less than what is required, then complete one of the following steps:

    • Delete unnecessary files from the /tmp directory to make available the space required.

    • Extend the file system that contains the /tmp directory. If necessary, contact your system administrator for information about extending file systems.

  • At least 8 GB of space for the Oracle Grid Infrastructure for a cluster home (Grid home). Oracle recommends that you allocate 100 GB to allow additional space for patches.

  • For IBM: Linux on System z, at least 3.8 GB of space for the Oracle Grid Infrastructure for a cluster home (Grid home).

  • At least 12 GB of space for the Oracle base of the Oracle Grid Infrastructure installation owner (Grid user). The Oracle base includes Oracle Clusterware and Oracle ASM log files.

  • For IBM: Linux on System z, at least 200 MB of space for the Oracle base of the Oracle Grid Infrastructure installation owner (Grid user).

  • 10 GB of additional space in the Oracle base directory of the Grid Infrastructure owner for diagnostic collections generated by Trace File Analyzer (TFA) Collector.

  • For Linux x86-64 platforms, if you intend to install Oracle Database, then allocate 6.4 GB of disk space for the Oracle home (the location for the Oracle Database software binaries).

  • For IBM: Linux on System z, if you intend to install Oracle Database, then allocate 5.2 GB of disk space for the Oracle home (the location for the Oracle Database software binaries).

If you are installing Oracle Databases, and you plan to configure automated database backups, then you require additional space either in a file system or in an Oracle Automatic Storage Management disk group for the Fast Recovery Area.

See Also:

Oracle Database Backup and Recovery User's Guide for more information about Fast Recovery Area sizing

2.4 Server Memory Minimum Requirements

Ensure that your system meets the following minimum requirements, depending on your system architecture

Note:

If you encounter an OUI error indicating inadequate swap space size, but your swap space meets the requirements listed here, then you can ignore that error.

2.4.1 Minimum Memory Requirements for Oracle Grid Infrastructure

Each system must meet the following minimum memory requirements:

  • At least 4 GB of RAM for Oracle Grid Infrastructure for a Cluster installations, including installations where you plan to install Oracle RAC.

  • Swap space equivalent to the multiple of the available RAM, as indicated in the following table:

    Table 2-1 Swap Space Required for 64-bit Linux and Linux on System z

    Available RAM Swap Space Required

    Between 4 GB and 16 GB

    Equal to RAM

    More than 16 GB

    16 GB of RAM


    Note:

    32-bit systems are no longer supported.

    Note:

    If you enable HugePages for your Linux servers, then you should deduct the memory allocated to HugePages from the available RAM before calculating swap space.

2.4.2 Shared Memory Requirements

If you intend to install Oracle Databases or Oracle RAC databases on the cluster, be aware that the size of the shared memory mount area (/dev/shm) on each server must be greater than the system global area (SGA) and the program global area (PGA) of the databases on the servers. Review expected SGA and PGA sizes with database administrators to ensure that you do not have to increase /dev/shm after databases are installed on the cluster.