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The Clusterware is INSTALLED on each node (on an ORACLE Home) and on the shared disks (the VOTING disks and the CSR file).

The Clusterware is installed on each node (on an Oracle Home) and on the shared disks (the voting disks and the CSR file).

• ACFS provides an Oracle Home shared FILE system or a general PURPOSE clustered file system on ASM storage.
• It NEEDS ASM DYNAMIC Volume MANAGER (ADVM) to communicate to the operating system.

Oracle Flex ASM INSTANCE when fails on a PARTICULAR NODE, then the Oracle Flex ASM instance is PASSED over to another node in the cluster.

Oracle Flex ASM instance when fails on a particular node, then the Oracle Flex ASM instance is passed over to another node in the cluster.

ACMS ENSURES global updates to System Global AREA (SGA) in a RAC set up.

ACMS ensures global updates to System Global Area (SGA) in a RAC set up.

The VIP is an alternate Virtual IP ADDRESS assigned to each node in a cluster. During a node failure the VIP of the failed node MOVES to the surviving node and relays to the application that the node has gone down. Without VIP, the application will WAIT for TCP TIMEOUT and then find out that the session is no longer live DUE to the failure.

The VIP is an alternate Virtual IP address assigned to each node in a cluster. During a node failure the VIP of the failed node moves to the surviving node and relays to the application that the node has gone down. Without VIP, the application will wait for TCP timeout and then find out that the session is no longer live due to the failure.

• The file SYSTEM and volume management in Oracle RAC should know about the architecture that is being used and it should be aware of the clusters that are involved in it. 
• Oracle supports automatic storage management that automates the storing of files and setup the communication in between the databases storage POOLS. 
• Oracle supports the high performance of the input and output of the storage subsystem by providing easy tools to use to MAXIMIZE it.
• They provide a way to balance the load across the available resources that ALLOWS the correct optimization of the file system and volume management. 
• Oracle RAC provides dynamic volume manager and it has a file system that contains the information of the cluster file system as WELL. 
• The cluster file system in oracle is called as (OCFS) and it has the connection with the databases that provide raw devices and command line features.

The CLUSTER Health Monitor (CHM) stores operating system metrics in the CHM repository for all NODES in a RAC cluster. It stores information on CPU, MEMORY, process, network and other OS DATA, This information can later be retrieved and used to troubleshoot and identify any cluster related issues. It is a DEFAULT component of the 11gr2 grid install. The data is stored in the master repository and replicated to a standby repository on a different node.

The Cluster Health Monitor (CHM) stores operating system metrics in the CHM repository for all nodes in a RAC cluster. It stores information on CPU, memory, process, network and other OS data, This information can later be retrieved and used to troubleshoot and identify any cluster related issues. It is a default component of the 11gr2 grid install. The data is stored in the master repository and replicated to a standby repository on a different node.

The background processes required for RAC are given as follows:

• ACMS – ATOMIC CONTROLFILE to MEMORY Service
• LMON – Global Enqueue Service Monitor
• LMD – Global Enqueue Service Daemon
• LMS – Global CACHE Service Process
• LCK0 – Instance Enqueue Process
• RMSN – Oracle RAC Management Processes
• RSMN – Remote Slave Monitor

The background processes required for RAC are given as follows: