Chapter 1. Understanding Caldera Volution Manager

Go here for info on the current status of SCO Linux products
Table of Contents
1.1. Understanding Caldera Volution Manager Terminology
1.2. How Caldera Volution Manager Works
1.2.1. Learning the Basics
1.2.2. Understanding the Details
1.2.2.1. Understanding the Computer Creation Daemon (volutionccd)
1.2.2.2. Running OpenSLP
1.2.2.3. Implementing DENS and Polling
1.2.2.4. Processing Object Changes

Caldera Volution Manager (VM) is a secure, web-based systems management solution that runs on an OpenLinux® 3.1.1 server. You can use VM to manage remote client systems that run recent versions of most Linux® operating systems, as well as Caldera Open UNIX 8, UnixWare® 7 and SCO OpenServer™.

After you install and configure the VM Server and VM Clients as described in the Installation Guide, you can:

You perform these tasks from the VM Management Console. The console displays the directory structure, and enables you to configure and schedule actions to apply to client systems. The console manages data stored on the VM Server, which contacts the clients with updates as needed.

This topic includes:

1.1. Understanding Caldera Volution Manager Terminology

Caldera Volution Manager uses specific terminology to describe its operating environment.

Action 

An action is a script, and a schedule that specifies when to run the script.

Computer Group 

A defined group of computer system objects which are labeled as a computer group in the directory structure. For example, you might create a computer group named engineering that consists of the computers eng1, eng2, and eng3. If you want to apply the same policy on all three systems, you can link the policy to engineering, rather than linking it to each individual system. You can also create a computer group based on a hardware or software inventory. For example, you might create a group containing all systems that have a particular model of sound card.

Container 

A logical grouping of items within the directory structure. A policies container might hold all of your policies, while a profiles container might include all of your software profiles. Each container has a unique name.

DENS 

The Distributed Events Notification System is used by the VM Server to notify client systems that a change has taken occurred. The DENS daemon (densd) runs by default. The alternative to DENS is polling, which is used for systems that cannot access densd because they are located outside the firewall or are not always connected to the network. See Section 4.1.

Directory Structure 

The organization of objects and containers in a hierarchical tree. This tree can be traversed using the Contents and Current Location panes in the VM Management Console, or you can use Go to Object to search for specific objects. The Installation Guide provides information about configuring the directory service for your network.

LDAP 

Lightweight Directory Access Protocol. This protocol provides the directory service used by VM to display and manage client objects from the VM Management Console. OpenLDAP is included with VM. The installation process also allows you to support Novell NDS eDirectory and Netscape iPlanet if required. See the Installation Guide for additional details.

Link 

An internal linking, in the directory structure, of an action, profile, or policy to a particular container, computer, or computer group.

Object 

A manageable item, such as a computer, a hard disk, a printer, or a software package. Each managed object is displayed in the Contents pane of the VM Management Console. This display is organized as a directory structure similar to a filesystem.

Profiles, policies, actions, computers, computer groups, and software packages are all special types of objects and are also a part of the Directory Structure.

OpenSLP 

OpenSLP is an open source implementation of the Service Location Protocol (SLP), a protocol that allows for services to be advertised and to be accessed by clients. Caldera created the open source version, OpenSLP, which is freely available to the open source community.

Policy 

An object that holds configuration information. A policy can be applied to a client by linking the policy to a container, computer, or computer group. Caldera Volution Manager provides sample policies for Health, Inventory, Printer, Gateway, and DENS. You can modify these to suit your needs.

Polling 

An alternative to usingDENS. If DENS is not available you can set up the client to contact theVM Server to poll for directory changes (configuration changes or actions to perform).

Profile 

A list of the software packages to be installed, removed, or updated for a particular computer or group of computers. You can define multiple profiles based on organizational units (such as engineering, sales), system types (web server, workstation), or any other grouping. Profiles can also contain pre or post-install (or remove) scripts that execute when a package is installed or removed.

Software Repository 

A container that holds objects corresponding to software packages you can distribute to clients. Supported package formats include RPM (for Linux systems), custom (for SCO OpenServer), and pkg (for UnixWare 7 and Open UNIX 8). Packages are added to the Software Repository automatically by the volutionsrd daemon after you place the software package binaries in package distribution directories. The package distribution directories are defined during the VM installation process.

volutionsrd 

The Software Repository Daemon (SRD), which creates software package objects in the LDAP directory that correspond to the software package binaries that you place in the package distribution directories.

Caldera Volution Manager Client
  

A Client is a Linux system or Unix system that can be managed by a VM Server. Each installed client runs the VM Client Daemon (volutiond). For information about installing a VM Client, see the Installation Guide.

Caldera Volution Manager Management Console
  

The VM Management Console is a browser-based interface used to perform all management tasks. From the console, you can add, remove, and edit profiles and policies, create actions to implement those policies, and link the actions to containers, computers or computer groups. The VM Management Console is installed and runs on the VM Server.

Caldera Volution Manager Server
  

A VM Server is a Caldera OpenLinux 3.1.1 (or newer) server system running VM Server software. This includes the computer creation daemon (volutionccd) which adds client computers to the directory structure, the DENS daemon (densd) which acts as an event scheduler, and the software repository daemon (volutionsrd) which adds distributable package objects to the Software Repository. For information on installing the VM Server, see the Installation Guide.

volutiond 

The VM Client daemon, which manages all VM activity on the client including authentication and interchange with the VM Server.

volutionccd 

The VM Computer Creation Daemon (volutionccd), also known as the CCD, is contacted by client systems that cannot authenticate to the LDAP directory. The CCD either locates the computer's existing computer object or creates a new one. This information is then passed back to the computer which then authenticates back to LDAP as that object. The CCD can handle up to 100 simultaneous requests for new computer objects.

1.2. How Caldera Volution Manager Works

This topic explains how Caldera Volution Manager operates and provides an overview of its capabilities. This topic includes:

1.2.1. Learning the Basics

Caldera Volution Manager implements an object-oriented, client-server network architecture, meaning that:

  • Data about the managed systems and their hardware and software components are stored as discrete objects that can be viewed and manipulated using the VM Management Console. For example, a computer, a hard drive, a network card, and a software package are all represented as objects.

  • Objects are organized into a hierarchical directory structure, from the top level (your organization) to progressively lower levels (for example: computer group, computer, hard disk, partition).

  • Additional special objects also appear in the directory structure. These include container objects (o, ou and computer) and activity objects (such as profiles, policies, and actions).

  • These objects are managed by the VM Server after collection from the client systems or creation using the VM Management Console. Tasks such as updating a printer, creating a hardware inventory, or installing a software package all take place by manipulating objects on the server using the console. These changes are then communicated over the network to affected clients, where the configuration changes are implemented.

You access objects using the VM Management Console. The console enables you to:

  • set console preferences

  • browse all objects (using an expandable/collapsible view of the directory structure)

  • manipulate the objects by performing actions and implementing profiles and policies

See Section 2.1 and Section 2.2 for information about starting and using the console.

1.2.1.1. Performing Key Management Tasks

Key management tasks include:

  • creating and updating a software profile to distribute software to client systems

  • updating a default policy or creating your own action to perform other system management tasks such as inventorying hardware, updating printers, or monitoring system use

  • linking a profile or policy to a computer or computer group to designate the clients to receive configuration changes

  • scheduling these changes

1.2.1.1.1. Understanding Profiles and the Software Repository

A profile is an object that lists the software to be installed, updated, or removed from a client or group of clients. When you create a profile, you specify the software to be updated, any installation flags, any special scripts to be run prior to or after installation, and you schedule when the profile is to run.

Any software you want to install, update, or remove must exist in a secure directory in the Software Repository. The Software Repository is an object container that contains objects corresponding to software packages you intend to distribute to clients. The Software Repository is created automatically when you install Caldera Volution Manager.

The Software Repository package distribution directories are defined when you install Caldera Volution Manager. The default base distribution directory is /opt/volution/srdfiles. Packages are added to the Software Repository automatically by the volutionsrd daemon after you place the software package binaries in a package distribution directory.

For more information about distributing software, see Chapter 3.

1.2.1.1.2. Understanding Policies

A policy is an object that holds configuration information that sets parameters for a specific type of action. A policy can be applied to a client by linking the policy to a container, computer, or computer group. The sample policies can be modified to suit your needs. With policies, you can:

  • inventory hardware and software on one or more clients

  • monitor the use of various hardware components such as CPU, disk space, and memory

  • add a local or networked printer to one or more clients

  • define whether a computer should use DENS or poll for directory changes

For more information about implementing policies, see Chapter 4

1.2.1.1.3. Linking Profiles and Policies to VM Clients

Creating a profile or policy defines the activity that you want to perform. Linking the profile or policy to a container, computer or computer group determines on which systems the activity is implemented.

Links create a logical relationship between objects. By linking, you connect the activity object (such as a profile) to a virtual representation of an object (such as a computer or a computer group).

For more information about linking, see Section 2.4.2.

1.2.1.1.4. Scheduling Changes

After linking a policy to a container, you need to schedule the activity. You do this by creating an action, another of the special object types. Actions can take place immediately, at a pre-determined time, or on a recurring basis from daily to yearly.

You do not need to create an action to schedule implementation of a profile - the schedule is determined when you create or edit the profile.

1.2.1.1.5. Understanding Communication Modes: Real Time and Polling

By default, client-server communication is performed in real time. When the VM Server has an activity it needs to perform on a client the client is notified by the Distributed Event Notification System (DENS) that runs as a daemon on the VM Server system.

Sometimes, DENS cannot notify the client system. For example, if one of the clients is a laptop that is not usually connected to the network, synchronous updates fail most of the time. Also, systems located outside a corporate firewall often cannot access DENS. In these cases, you can implement a polling scheme. This allows for updates at a particular time when you know the laptop is available, and it also resolves most firewall issues.

For more information about creating a polling scheme, see Section 4.1.

1.2.1.1.6. Performing Other Management Tasks

Other management tasks might include:

  • increasing security by working with security certificates and reacting to potential intruders (see the Installation Guide)

  • using Caldera Volution Online to obtain software updates, alerts, and patches (see Section 3.1.3)

  • using diagnostic tools to troubleshoot VM Server and VM Client problems (see Section 5.2)

1.2.2. Understanding the Details

This topic describes the underlying technologies and processes that support Caldera Volution Manager.

1.2.2.1. Understanding the Computer Creation Daemon (volutionccd)

The computer creation daemon (volutionccd) adds new clients to the VM Server directory structure automatically as they are installed and configured. When the VM Client daemon (volutiond) initializes on a client system, it attempts to authenticate to the repository. If this is the initial loading, the authentication fails. When the failure occurs, the client daemon uses OpenSLP to look for the computer creation daemon. The computer creation daemon then searches for the computer in the repository. If it is found, the daemon changes its credentials and then returns them. If the computer is not found, the daemon creates a new computer object in the configured location and returns those credentials.

1.2.2.2. Running OpenSLP

The Open Service Location Protocol (OpenSLP) is based on RFCs 2165, 2608, 2609, and 2614. OpenSLP provides a standard way for services to advertise and for consumers to find the advertised services. This protocol eliminates the need to configure each client on which Caldera Volution Manager is installed. OpenSLP allows the software running on a client to locate all of the services it needs without having to set up or modify its configuration files. OpenSLP was developed by Caldera and is freely available to the open source community.

1.2.2.3. Implementing DENS and Polling

The Distributed Events Notification System (DENS) densd daemon notifies a client when the client's computer object, or an object related to the client's computer object, has been changed. This notification is independent of the action that implements the change on the client system.

If DENS is not available, a system must poll for directory changes. In this mode, clients poll the LDAP directory directly as often as the schedule indicates. See Section 4.1

1.2.2.4. Processing Object Changes

When clients are installed, they query OpenSLP for the DENS server. The client then registers with the DENS server to receive events on object changes that affect that computer, such as changes to its computer object or to a linked policy, profile, or action. After an object is changed using the VM Management Console, the console notifies DENS of the change. DENS then notifies all affected clients. When the client receives notification of a change, it contacts the LDAP server to check for changes. Any linked objects that have changed are read and applied.