Oracle Database Tips by Donald Burleson

Oracle10g Grid Computing with RAC
Chapter 6 - Install, Configure and Database Creation

A Note on SKGXP, SKGXN Libraries

For example, Veritas DBE/AC provides a module to implement the skgxp functionality. This is available in the form of a library (libskgxp9.so), which is dynamically linked by Oracle at execute time. This skgxp interface utilizes the LLT multiplexer (LMX) via ioctl() calls. The LMX module is a kernel module designed to receive communications from the skgxp module and pass them to the correct process on the correct instance on other nodes. The module "multiplexes" communications between multiple related processes into a single multi threaded LLT port between systems.

Oracle has provided another set of APIs to provide the membership information to the RAC system. This is known as system kernel generic interface node membership (skgxn). Oracle RAC makes specific skgxn calls and gets the required membership information. The skgxn library, in turn, makes ioctl() calls to a kernel module for membership information. This kernel module is known as VCSMM (VCS membership module) and is implemented in library libskgxn2.so. Oracle uses the linked skgxn library to communicate with VCSMM, which obtains membership information from GAB.

General Installation Steps

Figure 6.4 shows the basic flow of the cluster configuration, shared storage structures preparation and installation of the Oracle software, and creation of the database. This involves a sequential process of tasks.