About Oracle Cluster Registry
Oracle Cluster Registry (OCR) is a file This contains information about the Cluster node list and instance-to-node mapping Information. OCR also contains information about the Oracle Clusterware resource profiles for resources so you have customized. The voting disk data is also backed up in OCR.
OCR contains the node information of the cluster as well as the mapping information of the instance to the node. Also includes custom cluster resources, voting disk's data is also backed up into OCR
Each node in a cluster also have a local copy of the OCR, called an Oracle local Registry (OLR), that's created when Oracl E Clusterware is installed. Multiple processes on each node has simultaneous read and write access to the OLR particular to the node on which they re Side, whether Oracle Clusterware is fully functional. By default, OLR are located at grid_home/cdata/$HOSTNAME. OLR
each node in the cluster also includes a local OCR backup, called OLR, that was created when the cluster was installed. Multiple processes at each node read and write local OLR at the same time. By default, OLR exists in $grid_home/cdata/$HOSTNAME. OLR
Managing the Oracle Clusterware Stack
Note:
Do not use Oracle Clusterware Control (CRSCTL) commands on Oracle entities (such as resources, resource types, and server Pools) that has names beginning with Ora unless you is directed to doing so by Oracle support. The Server Control utility (SRVCTL) is the correct utility to use on Oracle entities.
do not use the CRSCTL command to open the process name at the beginning of the ORA unless notified by Oracle Support. Start this process with Srvctl
Starting Oracle Clusterware
Your use of the Crsctl utility to manage Oracle clusterware. If the Oracle High Availability Services Daemon (OHASD) are running on all the cluster nodes and then you can start the entire Oracle Clusterware Stack (all the processes and resources managed by Oracle Clusterware), on all nodes in the cluster by Executing the following command on any node:
Crsctl Start Cluster-all
----If the OHASD process is already started on all nodes, you can use the command above to start the entire cluster.
You can start the Oracle clusterware stack on specific nodes by using THE-N option followed by a space-delimited list of Node names, for example:
Crsctl Start Cluster-n racnode1 racnode4
----Use the command above to start a single node in the cluster
To use the previous command, the OHASD process must is running on the specified nodes.
To start the entire Oracle clusterware stack in a node, including the OHASD process, run the following command on that nod E:
Crsctl Start CRS
-----Use the command above to start a cluster resource, including the OHASD process, but only on a single node.
Stopping Oracle Clusterware
To stop Oracle clusterware on all nodes with the cluster, execute the following command on any node:
Crsctl Stop Cluster-all
----Stop resources for all nodes in the cluster
The previous command stops the resources managed by Oracle Clusterware, the Oracle ASM instance, and all the Oracle Cluste Rware processes (except for OHASD and its dependent processes).
To stop Oracle Clusterware and Oracle ASM on select nodes, include The-n option followed by a space-delimited list of nod E names, for example:
Crsctl Stop Cluster-n racnode1 racnode3
----Stop a single node
If you don't include either the-all or The-n option in the Stop cluster command, then Oracle Clusterware and its manage D resources is stopped only on the node where you execute the command.
To completely shut down the entire Oracle clusterware stack, including the OHASD process, use the CRSCTL Stop CRS command. Crsctl attempts to gracefully stop the resources managed by Oracle Clusterware during the shutdown of the Oracle Clusterw is stack. If any resources that Oracle Clusterware manages is still running after executing the CRSCTL stop CRS command and then the C Ommand fails. You must then use THE-F option to unconditionally stop all resources and stop the Oracle clusterware stack, for example:
Crsctl Stop Crs-all-f
----Forcing the CRS off
Note:
When your shut down the Oracle Clusterware stack, you also shut down the Oracle Automatic Storage Management (Oracle ASM) I Nstances. If The Oracle Clusterware files (voting disk and OCR) is stored in a Oracle ASM disk group, then the-the-only-to-shut do WN The Oracle ASM instances is-shut down the Oracle Clusterware stack.
About Oracle Cluster Registry
