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Oracle® Database Installation Guide
10g Release 1 (10.1) for UNIX Systems: AIX-Based Systems, hp HP-UX, hp Tru64 UNIX, Linux, and Solaris Operating System
Part No. B10811-05
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C Using NAS Devices

If you have a network attached storage (NAS) device that has been certified through the Oracle Storage Compatibility Program (OSCP), you can use it to store the Oracle software, the Oracle database files, or both. This appendix provides guidelines for using a NAS storage device for Oracle software and database files. It includes information about the following:

General Configuration Guidelines for NAS Devices

See the documentation provided with your NAS device for specific information about how to configure it. In addition, use the following guidelines to ensure that the performance of the Oracle software meets your requirements:

Choosing Mount Points

This section provides guidelines on how to choose the mount points for the file systems that you want to use for the Oracle software and database files. The guidelines contained in this section comply with the Optimal Flexible Architecture recommendations. It contains information about the following:

Choosing Mount Points for Oracle Software Files

Oracle software files are stored in three different directories:

  • Oracle base directory

  • Oracle Inventory directory

  • Oracle home directory

For the first installation of Oracle software on a system, the Oracle base directory, identified by the ORACLE_BASE environment variable, is normally the parent directory for both the Oracle Inventory and Oracle home directories. For example, for a first installation, the Oracle base, Oracle Inventory, and Oracle home directories might have paths similar to the following:

Directory Path
Oracle base ($ORACLE_BASE) /u01/app/oracle
Oracle Inventory $ORACLE_BASE/oraInventory
Oracle home $ORACLE_BASE/product/10.1.0/db_1

For subsequent installations, you can choose to use either the same Oracle base directory or a different one, but every subsequent installation uses the original Oracle Inventory directory. For example, if you use the /u02/app/oracle directory as the Oracle base directory for a new installation, the Oracle Inventory directory continues to be /u01/app/oracle/oraInventory.

To enable you to effectively maintain the Oracle software on a particular system, Oracle recommends that you locate the Oracle Inventory directory only on a local file system, if possible. If you must place the Oracle Inventory directory on a NAS device, create a specific directory for each system, to prevent more than one system from writing to the same Inventory.

Directory-Specific Guidelines

You can use any of the following directories as mount points for NFS file systems used to store Oracle software:


Note:

In the following examples, the paths shown are the defaults if the ORACLE_BASE environment variable is set before you start the Installer.

  • Oracle base directory or its parents (/u01/app/oracle for example)

    If you use the Oracle base directory of one of its parents as a mount point, the default location for all Oracle software and database files will be on that file system. During the installation, you might consider changing the default location of the following directories:

    • The Oracle Inventory directory (oracle_base/oraInventory)

      Specify a local file system or a host-specific directory on the NFS file system, for example:

      oracle_base/hostname/oraInventory
      
      
    • The Oracle database file directory (oracle_base/oradata)

      You might want to use a different file system for database files, for example, to enable you to specify different mount options or to distribute I/O.

    • The Oracle database recovery file directory (oracle_base/flash_recovery_area)

      Oracle recommends that you use different file systems for database and recovery files.

    If you use this mount point, all Oracle installations that use this Oracle base directory will use the NFS file system.

  • The product directory (oracle_base/product)

    By default, only software files will be located on the NFS file system. You can also use this mount point to install software from different releases, for example:

    /u01/app/oracle/product/9.2.0
    /u01/app/oracle/product/10.1.0/db_1
    
    
  • The release directory (oracle_base/product/10.1.0)

    By default, only software files will be located on the NFS file system. You can also use this mount point to install different products from the same release, for example:

    /u01/app/oracle/product/10.1.0/crs
    /u01/app/oracle/product/10.1.0/db_1
    /u01/app/oracle/product/10.1.0/companion_1
    
    
  • The Oracle home directory (oracle_base/product/10.1.0/db_1)

    By default, only software files will be located on the NFS file system. This is the most restrictive mount point. You can use it only to install a single release of one product:

    /u01/app/oracle/product/10.1.0/db_1
    
    

Choosing Mount Points for Oracle Database and Recovery Files

To store Oracle database or recovery files on a NAS device, you can use different paths depending on whether you want to store files from only one database or from more than one database:

  • Use the NFS file system for files from more than one database

    If you want to store the database files or recovery files from more than one database on the same NFS file systems, use paths or mount points similar to the following:

    File Type Path or Mount Point
    Database files /u02/oradata
    Recovery files /u03/flash_recovery_area

    When the Installer prompts you for the datafile and the recovery file directories, specify these paths. The DBCA and Enterprise Manager create subdirectories in these directories using the value you specify for the database name (DB_NAME) as the directory name, for example:

    /u02/oradata/db_name1
    /u03/flash_recovery_area/db_name1
    
    
  • Use the NFS file system for files from only one database

    If you want to store the database files or recovery files for only one database in the NFS file system, you can create mount points similar to the following, where orcl is the name that you want to use for the database:

    /u02/oradata/orcl
    /u03/flash_recovery_area/orcl
    
    

    Specify the directory /u02/oradata when the Installer prompts you for the datafile directory and specify the directory /u03/flash_recovery_area when the Installer prompts you for the recovery file location. The orcl directory will be used automatically either by DBCA or by Enterprise Manager.

Creating Files on a NAS Device for Use with ASM

If you have a certified NAS storage device, you can create zero-padded files in an NFS mounted directory and use those files as disk devices in an ASM disk group. To create these files, follow these steps:


Note:

To use files as disk devices in an ASM disk group, the files must be on an NFS mounted file system. You cannot use files on local file systems.

  1. If necessary, create an exported directory for the disk group files on the NAS device.

    See the NAS device documentation for more information about completing this step.

  2. Switch user to root:

    $ su -
    
    
  3. Create a mount point directory on the local system:

    # mkdir -p /mnt/oracleasm
    
    
  4. To ensure that the NFS file system is mounted when the system reboots, add an entry for the file system to the appropriate mount file for your operating system (/etc/filesystems on AIX, /etc/vfstab on Solaris, and /etc/fstab on other platforms).

    For more information about editing the mount file for your operating system, see the man pages. For more information about recommended mount options, see the "NFS Mount Options" section.

  5. Enter a command similar to the following to mount the NFS file system on the local system:

    # mount /mnt/oracleasm
    
    
  6. Choose a name for the disk group that you want to create, for example nfsdg.

  7. Create a directory for the files on the NFS file system, using the disk group name as the directory name:

    # mkdir /mnt/oracleasm/nfsdg
    
    
  8. Use commands similar to the following, depending on your operating system, to create the required number of zero-padded files in this directory:

    • Solaris:

      # mkfile 1024M /mnt/oracleasm/nfsdg/disk1
      
      
    • Other operating systems:

      # dd if=/dev/zero of=/mnt/oracleasm/nfsdg/disk1 bs=1024k count=1000
      
      

    Both examples create 1 GB files on the NFS file system. You must create one, two, or three files respectively to create an external, normal, or high redundancy disk group.

  9. Enter the following commands to change the owner, group, and permissions on the directory and files that you created:

    # chown -R oracle:dba /mnt/oracleasm
    # chmod -R 660 /mnt/oracleasm
    
    
  10. When you are creating the database, edit the ASM disk discovery string to specify a regular expression that matches the file names you created. For example, you might specify a disk discovery string similar to the following:

    /mnt/oracleasm/nfsdg/*
    
    

NFS Mount Options

When mounting an NFS file system on your system, Oracle recommends that you use the same mount point options that your NAS vendor used when certifying the device. See your device documentation or contact your vendor for information about recommended mount-point options.

In general, most vendors recommend that you use the NFS mount options listed in the following table. See your operating system or NAS device documentation for more information about the specific options supported on your platform.

Option Description
hard Generate a hard mount of the NFS file system. If the connection to the server is lost temporarily, Oracle continues to retry the connection until the NAS device responds.
bg Try to connect in the background if connection fails.
proto=tcp (or tcp on Linux) Use the TCP protocol rather than UDP. TCP is more reliable than UDP.
vers=3 (or nfsvers=3 on Linux) Use NFS version 3. Oracle recommends that you use NFS version 3 where available, unless the performance of version 2 is higher.
suid Allow clients to run executables with SUID enabled. This option is required for Oracle software mount points.
rsize, wsize The number of bytes used when reading or writing to the NAS device. A value of 8192 is often recommended for NFS version 2 and 32768 is often recommended for NFS version 3.
nointr (or intr) Do not allow (or allow) keyboard interrupts to kill a process that is hung while waiting for a response on a hard-mounted file system.

Note: Different vendors have different recommendations about this option. Contact your vendor for advice.

noac Disable attribute caching.

Note: You must specify this option for NFS file systems where you want to install the software. If you do not use this option, the Installer will not install the software in the directory that you specify.

forcedirectio (Solaris) Use direct I/O (no buffering) for data transfers.

Note: Use this option for file systems that contain only Oracle database files. Do not use it for a file system that contains Oracle software.