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

automatically transfer control of the package to another cluster node, allowing services to
remain available with minimal interruption.
• System multi-node packages. There are also packages that run on several cluster nodes at
once, and do not fail over. These are called system multi-node packages and multi-node
packages. As of Serviceguard Extension for RAC A.11.18, the non-failover packages that
are supported are those specified by Hewlett-Packard, and you can create your own multi-node
packages. For example, the packages HP supplies for use with the Veritas Cluster Volume
Manager (CVM) and the Veritas Cluster File (CFS) System (on HP-UX releases that support
Veritas CFS and CVM. Also, see “About Veritas CFS and CVM from Symantec” (page 16)).
• Multi-node package. A system multi-node package must run on all nodes that are active in
the cluster. If it fails on one active node, that node halts. A multi-node package can be
configured to run on one or more cluster nodes. It is considered UP as long as it is running
on any of its configured nodes.
NOTE: In RAC clusters, you create packages to start and stop Oracle Clusterware and RAC itself
as well as to run applications that access the database instances. For details on the use of packages
with Oracle Clusterware and RAC, refer to “RAC Instances” (page 29)
Serviceguard Extension for RAC Architecture
This chapter discusses the main software components used by Serviceguard Extension for RAC.
The following is a list of components:
• Oracle Components
◦ Custom Oracle Database
• Serviceguard Extension for RAC Components
◦ Group Membership Services (RAC)
• Serviceguard Components
Package Manager◦
◦ Cluster Manager
◦ Network Manager
• Operating System
Volume Manager Software◦
◦ HP-UX Kernel
Group Membership Daemon
In addition to the Serviceguard daemon processes mentioned in Chapter 3 of the Managing
Serviceguard user’s guide, there is another daemon that is used by Oracle to enable communication
with Serviceguard Extension for RAC:
• cmgmsd—Group Membership Daemon for RAC 10g or later
This HP daemon provides group membership services for Oracle Real Application Cluster 10 g or
later. Group membership allows multiple Oracle instances to run on the same cluster node. GMS
is illustrated in Figure 2 (page 14).
Overview of SGeRAC and Cluster File System (CFS)/Cluster Volume
Manager (CVM)
SGeRAC supports Veritas Cluster File System (CFS)/Cluster Volume Manager (CVM) from Symantec
through Serviceguard. CFS and CVM are not supported on all versions of HP-UX (on HP-UX releases
Serviceguard Extension for RAC Architecture 15