Discussing ZENworks for Servers 3 Policies

ZENworks for Servers 3 introduces policies to the servers in your network. These policies are configuration or functional behaviors that may be applied to one or many elements or devices in the network. These policies function similarly to those introduced to the network environment by the ZENworks for Desktops product. Unlike policies in other ZENworks products, ZENworks for Servers 3 has moved to distributed policies for most of their functions. This allows the administrator to send policies to servers that are not in the same tree or have any eDirectory association. The agents running on the server DO NOT walk the tree looking for the policies that are associated directly or indirectly with the server. The agents, when they receive the Policy Distribution package, extract the package and then apply the configuration and other features that are activated in the policies. The only exceptions are that the inventory agents on the server look for a Server Package and a Service Location Package to determine their configuration and database, and that the distributor looks for a TED policy in a Service Location Package, associated to a subscriber and/or distributor object.

Only the distributor in ZENworks for Servers 3 looks for policies for the distributor and the destination subscribers. The distributor uses the Search Policy that may be activated in the Container Policy package to determine the search's behavior. The Search Policy may notify the distributor to walk only to a container, for example, rather than to walk all the way to the root of the tree (potentially crossing WAN boundaries) looking for all the policies. You need to be careful how you place policies and where the search policy is located to ensure an efficient and minimal walking of the NDS tree.

In addition to the server policies and the search policy (in the container policy package) the distributor in ZENworks for Servers 3 looks for information concerning resources to use in the directory. These resources are identified in the Service Location Policy package. This package is traditionally created directly after installation, but this chapter also discusses this policy package and what resources are used in this package for ZENworks for Servers 3.

Although ZENworks for Servers 3 now delivers policies through the Policy Distribution Package, the traditional policies are still supplied and supported in ZENworks for Servers 3 administration tools so that the system can continue to provide policies to your ZENworks for Server 2 systems while you are in the process of migrating.

Understanding Platform-Specific Policies

ZENworks for Servers 3 allows the administration of specific policies for each platform that is supported in the ZENworks for Servers 3 system. By having a policy that is categorized for each type of platform, the administrator can make unique policies for each system. Each server receives the policies in the distribution package and executes the administrative configurations for its platform.

If you want to send a different set of polices to different groups of servers, then you must create a unique channel for each group of servers and subscribe the servers to the appropriate channel. Then you create a unique Policy Distribution Package for each set of servers and place each package in the appropriate channel. The servers subscribed to the channel receive and implement the policies in the package. Remember you can have a subscriber subscribe to any number of channels.

ZENworks for Servers 3 not only incorporates policies for NetWare; it has added policies for Windows, Linux, and Solaris.

Plural Versus Cumulative Policies

ZENworks for Servers 3 has both plural and cumulative policies available in the system.

Cumulative policies are policies that can be activated in multiple policy packages effective for the server. All these policies would be applied to the server regardless of how they become effective for the server. If a server, for example, had two effective server policy packages (two distribution packages coming from the same channel, or two packages each coming from a different channel), and both these policy packages had set parameters activated, then all the set parameters in both the policy packages could be applied to the server. Not all policies are cumulative policies. Not all cumulative policies are plural policies.

Plural policies are policies where more than one instance of the policy may exist within the same policy package. Text file changes policy, for example, is a plural policy. You may create multiple text file changes policies so that several files may be changed by a single policy package. The plural policies have an Add button on their tab, enabling you to add multiple instances of the policy. All plural policies are cumulative, meaning that the plural policies from all the extracted policy packages are applied to the server.

Conflicts in policies can occur and measures exist to handle them. A possible conflict would be if the same set parameter existed in several policies that were effective for a specific server in NDS. When this occurs, the result is that the last policy that is applied to the server wins. The last policy applied is the package with the latest extraction time.