Applies to:
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Operating System(s) – RHEL 4.x, OEL 4.x, RHEL 5.x, OEL 5.x
Oracle Version(s): 11.2.x.x 

Author:
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Kai Yu

Problem:
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How do I store voting disks in ASM for Oracle 11gR2 Clusterware High Availability?

Solution:
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11gR2 clusterware voting disk files can be stored in ASM through the ASM diskgroup.  To ensure the high availability of the clusterware, it is highly recommended to store multiple voting disk files. When storing the voting disk files in ASM, the redundancy setting of the ASM diskgroup determines the number of voting disk files. The following settings are recommended for planning the proper configuration of ASM diskgroup that is used to store the voting disk files.

  • External Redundancy: The ASM diskgroup only has one failure group without mirroring and stores one voting disk file. It is recommended the disks have external redundancy RAID configuration to provide the storage high availability.
  • Normal Redundancy:  The ASM diskgroup requires three failure groups and it will provide three voting disks files.
  • High Redundancy: The ASM diskgroup requires five failure groups and it has five voting disk files.


Following the recommended setting above, administrators can configure the 11g R2 clusterware by storing the voting disk files in ASM:

  1. Based on the external storage redundancy and number of voting disks assigned select the appropriate redundancy setting for the ASM diskgroup. If there is no external redundancy for the storage disks or additional voting disk files are needed, it is recommended to select normal or high redundancy as the setting of choice for the ASM diskgroup.

    As an example, in this configuration the high redundancy setting for the ASM diskgroup has been selected. The ASM diskgroup has five ASM failure groups each of which is on one of the following ASM disks:

    ORCL:OCR1,
    ORCL:OCR2,
    ORCL:OCR3,
    ORCL:OCR4,
    ORCL:OCR5

  2. During 11g R2 Oracle Grid Infrastructure installation,select "Automatic Storage Management (ASM) In the storage selection step  as shown below:

  3. Specify the ASM diskgroup name and select the proper redundancy level and the corresponding ASM disks.

    As shown in the example below, appropriately name your Disk Group (i.e. OCRVOTDSK)select high redundancy, and the five ASM disk to be used for OCR and VOTING disks:

    OR
    CL:OCR1,
    ORCL:OCR2,
    ORCL:OCR3,
    ORCL:OCR4,
    ORCL:OCR5





  4. After the Grid Infrastructure installation completes, login to the ASM instance to check the ASM diskgroup redundancy setting and list the voting disk files using the command of 'crsctl query css votedisk'.