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ASM imposes the following limits:

• 63 DISK groups in a storage system
• 10,000 ASM disks in a storage system
• Two-terabyte MAXIMUM storage for each ASM disk (non-EXADATA)
• Four-petabyte maximum storage for each ASM disk (Exadata)
• 40-exabyte maximum storage for each storage system
• 1 million files for each disk group
• ASM file size limits (database limit is 128 TB):

1. External redundancy maximum file size is 140 PB.
2. Normal redundancy maximum file size is 42 PB.
3. High redundancy maximum file size is 15 PB.

ASM imposes the following limits:

REBALANCE time is heavily driven by the THREE items:
1) Amount of DATA CURRENTLY in the diskgroup
2) IO bandwidth AVAILABLE on the server
3) ASM_POWER_LIMIT or Rebalance Power Level

Rebalance time is heavily driven by the three items:
1) Amount of data currently in the diskgroup
2) IO bandwidth available on the server
3) ASM_POWER_LIMIT or Rebalance Power Level

• OCFS (Release 1 or 2)
• RAW devices
• third PARTY CLUSTER FILE system such as GPFS or Veritas

• Oracle Real Application Clusters are the key COMPONENTS of the EXISTING architecture.
• It provides directions and management of the applications that needs to be architect using the architecture.
• It provides high scalability of the applications that is being RUN on a single server and it takes the advantage of lower cost commodity hardware to reduce the cost.
• It enables the Oracle database to be run and maintained using the business application that are on the server pools and involves packaged products as well.
• It provides a way to integrate the in-house applications that are developed using the oracle database and its TECHNOLOGY.
• It allows easy management of the server by providing the ability to remove the server as a single POINT of failure in the database application environment.

A CLUSTER File SYSTEM (CFS) is a file system that MAY be accessed (READ and write) by all members in a cluster at the same time. This implies that all members of a cluster have the same view.

A cluster File System (CFS) is a file system that may be accessed (read and write) by all members in a cluster at the same time. This implies that all members of a cluster have the same view.

• Oracle RAC consists of a database that is represented in a clustered manner in the architecture.
• The cluster is the COLLECTION or pool of independent servers that make up one single system.
• Cluster architecture provides more flexibility to manage and follow a modular incremental APPROACH to improve the FAULT errors and PROVIDE an incremental system.
• This architecture provides the maximum security in terms of ensuring high AVAILABILITY of the resources to the users.
• It provides the resources on demand and provides hardware architecture such that a single point of failure is being removed.
• The architecture provides the decoupling of the Oracle instance like the process and memory that are running on the server from the Oracle database.

We need to stop and DELETE the INSTANCE in the node first in INTERACTIVE or silent mode. After that ASM can be removed using SRVCTL tool as follows:

• srvctl stop asm -n node_name
• srvctl remove asm -n node_name
• We can verify if ASM has been removed by issuing the following command:
• srvctl config asm -n node_name

We need to stop and delete the instance in the node first in interactive or silent mode. After that ASM can be removed using srvctl tool as follows:

The OCFS2 is the ORACLE (VERSION 2) Cluster FILE System which can be used for the Oracle Real Application Cluster.

The OCFS2 is the Oracle (version 2) Cluster File System which can be used for the Oracle Real Application Cluster.

• Clustered database is just like a single database accessed by multiple instances that are running on the server.
• The instances are being RUN separately or individually on the server POOL and when the demands rise they are shifted to acquire more space ACCORDING to the requirements.
• Clustered database provides dynamic access to the database and on the demand of additional resources they are added to the server pool.
• If one cluster is taking up the load then that load is shared between other clusters running on the server and the application services are provided in a much faster and better way.
• This also allows the adding of additional resources dynamically to the server pool with no DOWNTIME and the application starts running SOON it is deployed on the server.

• OCFS (RELEASE 1 or 2)
• ASM
• raw devices
• third PARTY cluster file system such as GPFS or VERITAS

• Cache function is used to show the storage of the information in the clustered network with the Oracle database.
• This uses the database transfer medium and it involves two nodes where one reads the data block from the disk and another write the data to the same disk.
• It provides very good performance and increases the flexibility in terms of execution of the application that is using the platform.
• RAC uses a dedicated server for its network CONNECTION and the cache fusion is an internal part to the CLUSTER.
• It uses the same database and keeps the things in the cache till the information is not needed anymore by any other application. It queries the data only when it totally necessary to do it.
• The query from the user ALWAYS results in the most CURRENT version even after the data is being modified.

HP Tru64 UNIX, VERITAS, MICROSOFT

HP Tru64 Unix, Veritas, Microsoft

• The Hardware Architecture of the Oracle RAC clusters provides a shared architecture with the server POOLS and allows all the storage devices to be shared.
• Hardware Architecture supports different types of storage networks like Network attached storage (NAS), Storage Area Network (SAN) and SCSI disks.
• Hardware architecture is such that it provides APPROPRIATE choices for the storage pools and system that provides SCALABILITY and flexibility to the overall system.
• The architecture should contain the INPUT and output for the application that NEED to be developed and then the system can have more scalability.
• Hardware architecture supports more application to be added in the server pool and allows better integration of services.

The BASE software is INSTALLED on each NODE of the CLUSTER and the DATABASE storage on the shared disks.

The base software is installed on each node of the cluster and the database storage on the shared disks.

• Oracle’s cloud server provides scalability by adding more servers to a pool when there is a requirement of any processing power or space.
• Provision to pay per hour/use as per the requirement, to, keep the overall COST low and build the functionality on the HIGH-end systems.
• Oracle RAC provides the PLATFORM’s architecture as it provides low-cost hardware platform to deliver high quality service and provide more scalability and AVAILABILITY.
• This reduces the administration cost and provides good management techniques and tools to monitor the services.
• This allows the users to build their own infrastructure on the basis of cloud.

This is POSSIBLE by USING a RAW DEVICE.

This is possible by using a raw device.

• Oracle RAC requires an active connection of the network to the LAN (Local Area Network) so that the database server can be found and CONNECTED.
• The database server is further having connections with application servers that STORE the applications and allow user to transfer their data.
• The connection is required with the server pool so that the transfer of services and applications can be done on demand basis.
• The interconnection between the networks is really important as it has to maintain the overall flow of the pools and the resources.
• Oracle RAC provides support to redundant interconnects RELATIVELY and it provides an overall infrastructure solution.
• The LOAD balancing and inter-node messaging can be handled more CAREFULLY when the networks or the servers are interconnected to each other.

Single Client Access Name (SCAN) is s a new Oracle Real Application Clusters (RAC) 11G Release 2 feature that provides a single name for CLIENTS to access an Oracle Database running in a cluster. The benefit is clients using SCAN do not need to change if you add or remove NODES in the cluster.

Single Client Access Name (SCAN) is s a new Oracle Real Application Clusters (RAC) 11g Release 2 feature that provides a single name for clients to access an Oracle Database running in a cluster. The benefit is clients using SCAN do not need to change if you add or remove nodes in the cluster.

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).

• Oracle Real Application (RAC) provides the INTERACTION of executable file with the Oracle database.
• It allows the running of any PACKAGED or custom built application with the Oracle database that is running on a server POOL.
• It provides very HIGH level of availability, flexibility and scalability to run the application and store it to the database.
• It CREATES the database such that if the pool fails then the database is continued to run from the remaining servers and the load can be distributed.
• It makes it easier for the administrator to maintain many servers at the same time by load-balancing techniques and providing provision to add more and more servers when the load increases.