Clones were initially conceived as a convenient way to start N instances of an IP resource and have them distributed throughout the cluster for load balancing. They have turned out to quite useful for a number of purposes including integrating with Red Hat's DLM, the fencing subsystem and OCFS2.

You can clone any resource provided the resource agent supports it.

Three types of cloned resources exist.

Anonymous clones are the simplest type. These resources behave completely identically everywhere they are running. Because of this, there can only be one copy of an anonymous clone active per machine.

Globally unique clones are distinct entities. A copy of the clone running on one machine is not equivalent to another instance on another node. Nor would any two copies on the same node be equivalent.

Stateful clones are covered later in Section 10.3, “Multi-state - Resources That Have Multiple Modes”.

  <clone id="apache-clone">
    <meta_attributes id="apache-clone-meta">
       <nvpair id="apache-unique" name="globally-unique" value="false"/>
    </meta_attributes>
    <primitive id="apache" class="lsb" type="apache"/>
  </clone>