Using Serviceguard Extension for RAC, 10th Edition, April 2011

for up-to-date information at www.hp.com/go/hpux-serviceguard-docs —> HP
Serviceguard Extension for RAC.
CAUTION: Once you create the disk group and mount point packages, you must administer the
cluster with CFS commands, including cfsdgadm, cfsmntadm, cfsmount, and cfsumount.
You must not use the HP-UX mount or umount command to provide or remove access to a shared
file system in a CFS environment. Using these HP-UX commands under these circumstances is not
supported. Use cfsmount and cfsumount instead.
If you use the HP-UX mount and umount commands, serious problems could occur, such as writing
to the local file system instead of the cluster file system. Non-CFS commands could cause conflicts
with subsequent CFS command operations on the file system or the Serviceguard packages, and
will not create an appropriate multi-node package, which means cluster packages will not be
aware of file system changes.
IMPORTANT: To avoid cluster wide panics and/or database failures, Storage Foundation for
Oracle RAC (SFRAC/SFCFS for RAC) installations using Cluster Volume Manager (CVM) shared
disk groups must have a dgfailpolicy of "leave". For additional details, read the latest version of
this technote at
www.symantec.com/business/support/index?page=content&id=TECH144672
Overview of SGeRAC and Oracle 10g, 11gR1, and 11gR2 RAC
Starting with Oracle 10g RAC, Oracle has bundled its own cluster software. The initial release is
called Oracle Cluster Ready Service (CRS). CRS is used both as a generic term referring to the
Oracle Cluster Software and as a specific term referring to a component within the Oracle Cluster
Software. At subsequent release, Oracle generic CRS is renamed to Oracle Clusterware. Oracle
Clusterware is the generic term referring to the Oracle Cluster Software.
The Oracle Cluster Software includes the following components: Cluster Synchronization Services
(CSS), Cluster Ready Service (CRS), and Event Management (EVM).
CSS manages the Oracle cluster membership and provides its own group membership service to
RAC instances. When installed on a SGeRAC cluster, CSS utilizes the group membership service
provided by SGeRAC.
CRS manages Oracle's cluster resources based on configuration—including start, stop, and monitor,
and failover of the resources.
EVM publishes events generated by CRS and may run scripts when certain events occur.
When installed on a SGeRAC cluster, both the Oracle Cluster Software and RAC can continue to
rely on the shared storage capability, networking monitoring, as well as other capabilities provided
through Serviceguard and SGeRAC.
Oracle 10g/11gR1/11gR2 RAC uses the following two subnets for cluster communication purposes:
• CSS Heartbeat Network (CSS-HB)—Oracle Clusterware running on the various nodes of the
cluster communicate among themselves using this network.
• RAC Cluster Interconnect Network (RAC-IC)—Database instances of a database use this
network to communicate among themselves.
NOTE: In this document, the generic terms CRS and Oracle Clusterware will subsequently be
referred to as Oracle Cluster Software. The use of the term CRS will still be used when referring
to a sub-component of Oracle Cluster Software.
For more detailed information on Oracle 10g/11gR1/11gR2 RAC, refer to Chapter 2:
“Serviceguard Configuration for Oracle 10g, 11gR1, or 11gR2 RAC”.
Overview of SGeRAC and Oracle 10g, 11gR1, and 11gR2 RAC 17