Model-to-Install Comparisons

A Model-to-Install comparison compares the `just installed' state of the resources in a component or components to their current state on a given host or host set. You can specify that this comparison compares the model to hosts, host sets, or to component level.

A Model-to-Install comparison uses information about what components and subsequent resources have been deployed to a given host based on snapshot information. A snapshot is a record of the state of an installed component immediately after it has been deployed to a host. The component's XML model includes parameters that control the scope of this snapshot. For example, the XML model can list files, such as log files, that should be ignored during a comparison.

When the provisioning software performs a Model-to-Install comparison, the Master Server looks up the list of snapshots for all the components being compared. It sends this list to the Remote Agent on the host where the components are installed. The snapshot information includes rules for any files and directories that should be ignored during the comparison. The Remote Agent then processes these rules. Both Master Server and Remote Agents must be using the same locale for the Model-to-Install comparison to function properly.

Unlike Model-to-Model comparisons, which compare one ideal installation to another, Model-to-Install comparisons compare the actual state of the installed component or components at deployment time against their current state.