Using Serviceguard Extension for RAC, 10th Edition, April 2013

An example of a bottleneck created if we only have a package for Oracle Clusterware is this: if
we concentrate all storage management in the Oracle Clusterware package, then any time there
is a change in the storage configuration for one database (for example, an SLVM volume group
is added), we would have to modify the Oracle Clusterware package.
These are the main arguments in favor of having separate packages for Oracle Clusterware and
each RAC database. But then the question arises: how do we ensure that these packages start and
halt in the proper order? Prior to version A.11.17, SG/SGeRAC did not provide a mechanism for
package ordering.
Two new features are introduced in SG/SGeRAC that help us solve this problem: MNPs and simple
package dependencies. The combination of MNPs and simple package dependencies is a very
good fit for our problem of coordinating Oracle RAC and SGeRAC. We configure Oracle
Clusterware as one MNP and each RAC database as another MNP and we set up the database
MNPs to depend on the Oracle Clusterware MNP. This is the core concept of SGeRAC.
Both Oracle Clusterware and the RAC database are multi-instance applications well suited to being
configured as MNPs. Further, the use of MNPs reduces the total package count and simplifies
SGeRAC package configuration and administration. Simple package dependencies enable us to
enforce the correct start/stop order between the Oracle Clusterware MNP and RAC database
MNPs.
Serviceguard Extension for RAC Toolkit operation
In this section, we first discuss how SGeRAC organizes the flow of control through the combined
stack. Then we deal with the interactions of the toolkit, first with Oracle RAC, and then with the
storage management subsystems.
Figure 15 shows how the toolkit enables SGeRAC and Oracle Clusterware to work in harmony
and ensure proper sequencing between themselves and the resources they manage.
It shows Oracle Clusterware and the resources it manages, via its Cluster Ready Services (CRS)
component, in red and the SGeRAC package manager (PM) in blue, as well as the resources it
manages.
Each resource manager starts up and shuts down the resources it manages, honoring the
dependencies that it recognizes. The dependencies are shown in red or blue depending on whether
they are Oracle Clusterware dependencies or SGeRAC dependencies.
The storage packages (Oracle Clusterware Storage and Database Storage) and associated
dependencies only exist for CFS, and the ASM instance and associated dependencies only exist
when ASM is being used.
SGeRAC provides scripts for Oracle Clusterware MNP, ASMDG MNP, and RAC DB instance
MNP. The Oracle Clusterware MNP starts, stops, and checks the status of the Oracle Clusterware.
The ASMDG MNP mounts dismounts and monitors the status of ASM Disk groups. The RAC DB
instance MNP starts, stops, and checks the status of the RAC instance. Oracle Clusterware and
RAC instance auto-start have to be disabled (using Oracle specified commands and procedures,
as previously discussed in this chapter).
106 SGeRAC Toolkit for Oracle RAC 10gR2 or later