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Checking shared disks for SCSI-3 support

The shared storage for SF Oracle RAC must support SCSI-3 persistent reservations to enable I/O fencing. SF Oracle RAC uses two types of shared storage:

• Data disks that store shared data
• Coordinator disks that act as a global lock during membership changes. Coordinator disks are small LUNs (typically three per cluster)

When to check the shared disks for SCSI-3 support

You can choose to verify that the disks you plan to use for shared data storage or for coordinator disks at this time, before you configure the SF Oracle RAC components, or later, after configuring the components. In either case, review the guideline included in the installer and refer to the procedures in the section Setting up I/O fencing.

If you test the disks now and discover that the disks are not SCSI3 compliant, you can delay the configuration tasks until you obtain and verify compliant disks.

If, however, you have high confidence that the disks you plan to use are compliant, you can skip testing now and proceed with the configuration SF Oracle RAC components. You can test the storage later.

Checking that disks support SCSI-3 involves:

• Reviewing the guidelines for checking the disks
• Verifying that nodes have access to the same disk
• Using the vxfentsthdw utility to perform the check

Viewing guidelines for checking SCSI-3 support

Use the SF Oracle RAC configuration program to review this system check for SCSI support.

 To view guidelines for checking SCSI-3 support

1. Log in as root user.
2. Navigate to the directory containing the installation program:

   # cd /cdrom/cdrom0/storage_foundation_for_oracle_rac

3. Start the installsfrac script:

   # ./installsfrac -configure

By default, the installsfrac program uses SSH for remote communication. However, to use RSH, specify the -rsh option with the installsfrac program.

# ./installsfrac -rsh -configure

4. From the main menu, select Check systems for SFRAC.
5. Select Check I/O fencing disks.
6. Review the brief overview on testing disks for SCSI-3 compliance. If you desire to test the disks at this time, proceed to Setting up I/O fencing and use the procedures:
   • Verifying the nodes see the same disk
   • Testing the disks using the vxfentsthdw script