Requirements for Cloudera Manager
Cloudera Manager interacts with a diversity of entities such as operating systems, databases, and browsers. Cloudera provides information about which major release version and minor release version is supported, where available. In some cases, such as some browsers, a minor version may not be provided. After installing each element, upgrade to the latest patch version and apply any other appropriate updates. Note that the available updates may be specific to the operating system on which it is installed.
For example, you might be using CentOS in your environment. You could choose 6 as the major version and 2 as the minor version. These choices would mean you would be using CentOS 6.2. After installing this operating system, you would then apply any and all relevant CentOS 6.2 upgrades and patches.
For information on CDH4 requirements, see Supported Operating Systems for CDH4 in CDH4 Installation Guide.
For information on CDH3 requirements, see Supported Operating Systems for CDH3 in CDH3 Installation Guide.