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Donald K. Burleson

Oracle RAC Tips

Servers and Operating system

The first critical task is the selection of the right server (or node) and operating system to host the Oracle RAC database. Oracle maintains a certification matrix for supported servers and platforms. The certification is issued only after Oracle and other vendors conduct rigorous tests. Oracle will only support RAC on certified combinations of hardware and operating system. We strongly recommend that you check the server vendor for Oracle Certification Matrix even if they certify and market the cluster platform for other applications.

Oracle Certification Matrix is available at Oracle Metalink through the following simple steps:

  1. Connect and login to

  2. Click on the "Certify and Availability" button on the menu frame

  3. Click on View Certifications by Product hyperlink

  4. Choose "Real Application Clusters"

  5. Choose the correct platform.

The following factors are influential in deciding the number of nodes for the proposed cluster or whether the cluster file system can be used:

  • What kind of shared storage system will be chosen?

  • What kind of cluster software and which version will be used?

Here are some examples that illustrate application of the above factors:

  • Sun servers, combined with Sun Cluster 3.0, only support raw partitions for database files.

  • Using Sun Cluster with more than two nodes requires SCSI-3 Persistent Group Reservation (PGR) supporting storage such as Sun StoreEdge T3, Hitachi 9990, or EMC Symmetrix.

However, when we implement Sun Cluster with Veritas DBE/AC 3.5, we have the choice of using the cluster file system. Veritas DBE/AC also requires storage with SCSI-3 PGR. DBE/AC stands for Database Edition / Advance Cluster.

For the IBM AIX pSeries (RS/6000) Cluster, the maximum number of nodes is 8 if SSA disks are used. If VSD(s) are used, the maximum number of nodes is 128. Again, if the disks are shared through CLVM, the maximum number of nodes is 16. VSD stands for virtual shared disk.

When we use the O/S version of AIX 4.3 with cluster software of HACMP/ES (CRM) 4.4.X, we have to use the raw partitions for RAC database. However, when we use AIX 5.1, we have the option of using the cluster file system (GPFS).

We strongly recommend that the readers verify with the Oracle Certification matrix, as well as the vendor suppliers, in order to choose the right combination of RAC system components. Since these specifications are frequently updated, please check for the latest edition.

Oracle certifies the combination of UNIX and Clusterware for RAC implementation. The vendor is responsible for the hardware certification. We have presented some of these features in Fig 6.2, based on the information available at the time of writing.

Fig 6.2 RAC and Cluster Environment matrix

For more information, see the book Oracle 11g Grid and Real Application Clusters 30% off if you buy it directly from Rampant TechPress . 

Written by top Oracle experts, this RAC book has a complete online code depot with ready to use RAC scripts.  


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The definitive Oracle Script collection for every Oracle professional DBA


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