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Oracle Clusterware and Oracle RAC provide many utilites help to manage and maintenance the clusterware and database such as cluvfy, crsctl, srvctl, ocrcheck, oifcfg, ocrconfig and so on. I would like to share some of the utilities usage and tips with you from this post.

First of all, i would like to introduce cluvfy — a very very useful tool when you plan to install and configure a cluster. Below are some of the basic concepts regarding cluvfy (also named as CVU) such as stage, component and nodelist and so on.

What is Cluster Verification Utility (CVU)? What are its objectives and features?
CVU is a utility that is distributed with Oracle Clusterware. It was developed to assist in the installation and configuration of Oracle Clusterware as well as RAC. CVU will verify all the important components that are needed at different stages in configuring a RAC environment. The wide domain of verification provided by CVU ranges from initial hardware setup through fully operational cluster for RAC deployment and covers all the intermediate stages of installation and configuration of various components. The command line tool is cluvfy. Cluvfy is a non-intrusive utility and will not adversely affect the system or operational stack.

What is a stage?
CVU supports the notion of Stage verification. It identifies all the important stages in RAC deployment and provides each stage with its own entry and exit criteria. The entry criteria for a stage define a specific set of verification tasks to be performed before initiating that stage. This pre-check saves the user from entering into a stage unless its pre-requisite conditions are met. The exit criteria for a stage define another specific set of verification tasks to be performed after completion of the stage. The post-check ensures that the activities for that stage have been completed successfully. It identifies any stage specific problem before it propagates to subsequent stages; thus making it difficult to find its root cause. An example of a stage is “pre-check of database installation”, which checks whether the system meets the criteria for RAC install.

What is a component?
CVU supports the notion of Component verification. The verifications in this category are not associated with any specific stage. The user can verify the correctness of a specific cluster component. A component can range from a basic one, like free disk space to a complex one like Oracle Clusterware Stack. The integrity check for the Oracle Clusterware stack will transparently span over verification of multiple sub-components associated with Oracle Clusterware stack. Bundling of several relevant tasks as a component is of great use to the user for verifying a specific cluster component

What is nodelist?
A nodelist is a comma separated list of hostnames without domain. Cluvfy will run the requested verification on all nodes in the nodelist provided. Cluvfy will ignore any domain while processing the nodelist. If duplicate entities after removing the domain exist, cluvfy will eliminate the duplicate names while processing. Wherever supported, you can use ‘-n all’ to check on all the cluster nodes. Check “Do I have to type the nodelist every time for the CVU commands? Is there any shortcut?” for more information on nodelist and shortcuts.

What version of Oracle Clusterware or RAC is supported by CVU?
On Linux x86 and x86_64: The current CVU release supports Oracle Clusterware, Oracle RAC 10g, and Oracle RAC 11g. In other words, “the current version” of CVU can check 10g as well as 11g releases of Oracle Clusterware or RAC. However, it can not check or verify pre-10g(Oracle 9i) products.
On Solaris SPARC64, AIX, HPUX (PARISC and IA64): CVU is limitedly backward compatible to the previous Oracle Clusterware releases up to Oracle Database 10g Release 1. It works on the operating system versions supported by 11gR1, that would be Solaris 9, Solaris 10, AIX 5.3, HPUX 11.23 and HPUX 11.31 only.

What about discovery? Does CVU discover installed components?
At present, CVU’s discovery is limited to the following components. CVU discovers available network interfaces if you do not specify any interface in its command line. For storage related verification, CVU discovers all the supported storage types if you do not specify a particular storage. CVU discovers CRS HOME if one is available. CVU also discovers the statically configured nodelist for the cluster if an Oracle supported vendor clusterware or Oracle Clusterware is available