Using Serviceguard Extension for RAC, 3rd Edition, May 2006

Introduction to Serviceguard Extension for RAC
Overview of SGeRAC and Cluster File System (CFS)/Cluster Volume Manager (CVM)
Chapter 120
Overview of SGeRAC and Cluster File System
(CFS)/Cluster Volume Manager (CVM)
SGeRAC supports Cluster File System (CFS) through Serviceguard. For
more detail information on CFS support refer to the Managing
Serviceguard Twelfth Edition user’s guide.
Package Dependencies
When CFS is used as shared storage, the application and software using
the CFS storage should be configured to start and stop using
Serviceguard packages. These application packages should be configured
with a package dependency on the underlying multi-node packages,
which manages the CFS and CVM storage reserves.
Configuring the application to be start/stop through SG package is to
ensure the synchronization of storage activation/deactivation and
application startup/shutdown.
With CVM configurations using multi-node packages, CVM shared
storage should be configured in Serviceguard packages with package
dependencies.
Refer to the Managing Serviceguard Twelfth Edition user’s guide for
detailed information on multi-node package.
Storage Configuration Options
Prior to CFS, the only option in a SGeRAC cluster to provide shared
storage for a RAC cluster was through raw volumes, using either SLVM
or CVM that are used for Oracle data files. The application software is
installed on a local file system. In addition to SLVM and CVM, SGeRAC
supports CFS.
CFS provides SGeRAC with additional options, such as improved
manageability. When planning a RAC cluster, application software could
be installed once and be visible by all cluster nodes. A central location is
available to store runtime logs, for example, RAC alert logs.