Clusterware Stack Management and Troubleshooting - Expert Oracle RAC 12c - page 31

Two files of Oracle Clusterware ( OLR) and GPnP profile are stored in the grid home of the local file system of
each RAC node. OLR is the OCR's local version, and it stores the metadata for the local node and is managed by the
Oracle High Availability Services daemon ( OHASD ). OLR stores less information than OCR, but OLR can provide this
metadata directly from the local storage without the need to access the OCR stored in an ASM disk group. One OLR is
configured for each node, and the default location is in $GIHOME/cdata/<hostname>.olr . The location is also recorded
in /etc/oracle/olr.loc , or you can check it through the ocrcheck command:
$ cat /etc/oracle/olr.loc
olrconfig_loc=/u01/app/12.1.0/grid/cdata/knewracn1.olr
crs_home=/u01/app/12.1.0/grid
$ ocrcheck -local -config
Oracle Local Registry configuration is :
Device/File Name : /u01/app/12.1.0/grid/cdata/knewracn1.olr
The GPnP profile records a lot of important information about the cluster, such as the network profile and the VD.
The information stored in the GPnP profile is used when adding a node to a cluster. Figure 2-1 shows an example of the
GPnP profile. This file default is stored in $GRID_HOME/gpnp/<hostname>/profiles/peer/profile.xml.
Figure 2-1. GPnP profile
Clusterware Software Stack
Beginning with Oracle 11gR2, Oracle redesigned Oracle Clusterware into two software stacks: the High Availability
Service stack and CRS stack. Each of these stacks consists of several background processes. The processes of these two
stacks facilitate the Clusterware. Figure 2-2 shows the processes of the two stacks of Oracle 12cR1 Clusterware.