Best Practices for SGeRAC and Oracle RAC on HP-UX 11i, March 2009

configured with a dependency on the CFS MNP. The Oracle Clusterware MNP ensures the required

storage is available before signaling the start of Oracle Clusterware.

Each RAC database MNP ensures the storage for the database is started before starting the database

instance.

The init process monitors Oracle Clusterware. Oracle Clusterware monitors the database instance.

The MNP monitoring is to the extent that the MNP status reflects the status of what it has started. The

MNP does not restart the application. For instance, if Oracle Clusterware is halted outside the MNP,

the MNP will discover that Oracle Clusterware is no longer running and the MNP is halted.

Standard packages

Please note that synchronization using standard Serviceguard packages is also supported.

Extended Distance Cluster for RAC

SGeRAC supports Extended Distance Cluster for RAC (EDC) with CFS, CVM, ASM, and SLVM. The

standard basic configuration

consists of two datacenters where the servers and storage reside, and a

third site where the quorum server resides. The quorum server is required as a tie-breaker in the event

of loss of communications between the datacenters.

OCR and Voting Disk

Oracle 10.2.0.1 and later supports up to two copies of the OCR and up to three vote disks. For

Extended Distance Clusters (EDC), each copy of OCR and each vote disk are required to be

physically mirrored by software (CFS, CVM, SLVM) between the two data centers.

In the event of a loss of communication between the datacenters, the quorum server serves as a tie-

breaker for Serviceguard. The mirrored OCR and Voting Disks ensure that OC has access to local

physical copies for OC cluster reformation.

Binaries

For EDC configurations, it is recommended to maintain local storage for OC and RAC database

binaries and home to reduce inter-site traffic.

Database data files

Database data files are required to be physically mirrored to both datacenters when using CFS, CVM,

ASM or SLVM.

Database recovery data

For EDC, when using SLVM or CVM, the database recovery data reside locally and needs to be

made available to the RAC instance performing recovery.

The benefit of using CFS for database recovery data is the simplicity for which the recovery data is

available to all instances.

Conclusion

While there are many different supported configurations and combinations of SGeRAC, Oracle

Clusterware and Oracle RAC, by understanding the most common best practices, an administrator

may select the best choice for optimally management and availability.

See document “Understanding and Designing Serviceguard Disaster Tolerant Architectures, 1

Edition, December 2006” available at

http://docs.hp.com, Select High Availability, Select Metrocluster.