ServiceNow CMDB and Configuration Items: A Beginner's Guide

The Configuration Management Database (CMDB) is one of the most critical components of ServiceNow's IT Service Management capabilities. This comprehensive guide will help you understand CMDB fundamentals for your CSA exam and real-world practice.

What is the CMDB?

The Configuration Management Database (CMDB) is a centralized repository that stores information about all the components (Configuration Items) of your IT infrastructure and their relationships.

Key Characteristics:

• Single Source of Truth: Centralized information about IT assets
• Relationship Tracking: Shows how CIs relate to and depend on each other
• Version Control: Tracks changes to CIs over time
• Service Mapping: Connects technical infrastructure to business services

What are Configuration Items (CIs)?

A Configuration Item (CI) is any component that needs to be managed to deliver an IT service.

Common Types of CIs:

Hardware CIs:

• Servers
• Workstations
• Network devices (routers, switches)
• Mobile devices
• Printers

Software CIs:

• Applications
• Operating systems
• Databases
• Licenses

Non-Technical CIs:

• Documentation
• Service contracts
• Vendor information
• Business services

The CI Table Structure

All Configuration Items are stored in the Configuration Item [cmdb_ci] table, which serves as the parent table for all CI types.

CI Table Hierarchy:

cmdb_ci (Configuration Item)
├── cmdb_ci_computer (Computer)
│   ├── cmdb_ci_server (Server)
│   │   ├── cmdb_ci_linux_server
│   │   └── cmdb_ci_win_server
│   └── cmdb_ci_computer_workstation (Workstation)
├── cmdb_ci_netgear (Network Gear)
│   ├── cmdb_ci_ip_router (Router)
│   ├── cmdb_ci_ip_switch (Switch)
│   └── cmdb_ci_ip_firewall (Firewall)
├── cmdb_ci_service (Business Service)
└── cmdb_ci_appl (Application)

Essential CI Fields

Every Configuration Item includes these important fields:

Identification Fields:

• Name: Unique identifier for the CI
• Asset tag: Physical asset identifier
• Serial number: Manufacturer's serial number
• Model: CI model information

Operational Fields:

• Operational status: Current operational state
  • Operational
  • Non-Operational
  • Repair in Progress
  • Retired
• Install status: Installation lifecycle stage
  • Installed
  • In Stock
  • On Order
  • Pending Install
  • Retired

Relationship Fields:

• Owned by: Individual or department that owns the CI
• Managed by: Group responsible for managing the CI
• Supported by: Group providing support
• Location: Physical location of the CI

Business Context:

• Assignment group: Group assigned to manage the CI
• Support group: Group providing support
• Cost: Purchase or lease cost
• Purchase date: When the CI was acquired

CI Relationships

One of the CMDB's most powerful features is tracking relationships between CIs.

Common Relationship Types:

1. Depends on / Used by

• Server depends on Router
• Application depends on Database
• Business Service depends on Application

2. Runs on / Runs

• Application runs on Server
• Operating System runs on Computer

3. Contains / Contained by

• Server contains Hard Drive
• Rack contains Servers

4. Connects to / Connected by

• Server connects to Switch
• Switch connects to Router

Viewing Relationships:

To see CI relationships:

1. Open a CI record
2. Go to the CI Relationships related list
3. Or use the Relationship Formatter for visual display
4. Or view the Dependency Map for graphical representation

CI Lifecycle Management

Configuration Items move through distinct lifecycle stages:

1. Planning

• CI is identified and approved for acquisition
• Specifications are defined
• Budget is allocated

2. Procurement

• CI is ordered from vendor
• Receiving and inventory management
• Install Status: On Order

3. Deployment

• Physical installation or software deployment
• Configuration and testing
• Install Status: Pending Install → Installed
• Operational Status: Operational

4. Operations

• Day-to-day use and monitoring
• Regular maintenance and updates
• Change management applied to CI

5. Retirement

• End of life or replacement
• Data migration if needed
• Physical disposal or repurposing
• Install Status: Retired
• Operational Status: Retired

CMDB Best Practices

1. Keep Data Accurate

• Regular audits and reconciliation
• Automated discovery tools
• Clear ownership and accountability

2. Define Clear Naming Conventions

• Consistent naming patterns
• Include location, type, or function
• Example: SRV-NYC-DB-01 (Server-Location-Function-Number)

3. Maintain Relationships

• Document dependencies accurately
• Update relationships when changes occur
• Use Service Mapping for complex services

4. Set Up Discovery

• Use ServiceNow Discovery for automated CI population
• Schedule regular discovery scans
• Configure discovery credentials properly

5. Implement CI Verification

• Regular CI audits
• Reconcile CMDB with asset inventory
• Remove obsolete CIs

6. Control Access

• Limit who can create/modify CIs
• Use Access Control Lists (ACLs)
• Implement approval workflows for CI changes

CMDB Applications in ServiceNow

The CMDB integrates with many ServiceNow applications:

Incident Management

• Link incidents to affected CIs
• Identify patterns of CI failures
• Prioritize based on CI criticality

Change Management

• Assess change impact using CI relationships
• Identify all affected services
• Plan change windows based on CI dependencies

Service Mapping

• Map technical infrastructure to business services
• Understand service dependencies
• Visualize service architecture

Asset Management

• Track hardware and software assets
• Manage licenses and contracts
• Monitor asset lifecycle

Working with the CMDB

Creating a Configuration Item:

1. Navigate to Configuration > [CI Type]
   • Example: Configuration > Servers > All Servers
2. Click New
3. Fill in required fields:
   • Name
   • Serial number
   • Asset tag
   • Operational status
   • Install status
4. Add relationships if needed
5. Click Submit

Searching for CIs:

Method 1: Direct Navigation

• Navigate to specific CI type (Servers, Workstations, etc.)
• Use filters to find specific CIs

Method 2: Global Search

• Use the global search bar
• Type CI name or serial number
• Select from results

Method 3: CMDB Query Builder

• Advanced searches with multiple conditions
• Save queries for reuse

Updating CI Information:

1. Open the CI record
2. Modify fields as needed
3. Document changes in Work Notes
4. Save the record
5. Changes are automatically tracked in audit history

CI Discovery and Population

ServiceNow offers multiple ways to populate the CMDB:

1. Manual Entry

• Direct creation of CI records
• Best for small environments or special cases

2. Import Sets

• Bulk import from Excel or CSV
• Transform maps to match data to CI fields

3. ServiceNow Discovery

• Automated network scanning
• Discovers servers, workstations, applications
• Updates existing CIs automatically

4. Integration with Other Tools

• Connect to asset management systems
• Pull data from monitoring tools
• Sync with procurement systems

CMDB Health and Maintenance

Key Health Metrics:

Completeness

• Percentage of CIs with all required fields populated
• Target: >95%

Accuracy

• Percentage of CI data that matches reality
• Regular audits needed
• Target: >90%

Compliance

• CIs following defined standards and naming conventions
• Target: >95%

Relationship Coverage

• Percentage of CIs with documented relationships
• Target: >80%

CMDB Health Dashboard

Navigate to Configuration > CMDB Health to view:

• CI completeness scores
• Relationship coverage
• Duplicate CI detection
• Orphaned CIs (CIs without relationships)

CSA Exam Tips

For the ServiceNow CSA exam, make sure you know:

1. CMDB Definition: Centralized repository for Configuration Items
2. CI Definition: Any component needed to deliver an IT service
3. CI Table: cmdb_ci is the parent table
4. Key CI Fields: Name, Operational Status, Install Status
5. Relationship Types: Depends on, Runs on, Contains, Connects to
6. CI Lifecycle: Planning → Procurement → Deployment → Operations → Retirement
7. CMDB Applications: Incident, Change, Service Mapping, Asset Management

Common Exam Questions:

• "What is stored in the CMDB?" (Answer: Configuration Items)
• "What table stores all CIs?" (Answer: cmdb_ci)
• "What are the two main CI status fields?" (Answer: Operational Status and Install Status)
• "How are CIs related to each other?" (Answer: Through CI Relationships)

Practical Exercises

Exercise 1: Create a Server CI

1. Navigate to Configuration > Servers > All Servers
2. Click New
3. Fill in: Name, Serial Number, Asset Tag
4. Set Operational Status to "Operational"
5. Set Install Status to "Installed"
6. Save the record

Exercise 2: Create CI Relationships

1. Open a Server CI
2. In CI Relationships, click New
3. Select relationship type (e.g., "Depends on")
4. Select a parent CI (e.g., a Switch)
5. Save the relationship

Exercise 3: View Dependency Map

1. Open any CI with relationships
2. Click the View Map button
3. Explore the visual dependency graph
4. Identify upstream and downstream dependencies

Advanced CMDB Concepts

Service Mapping

• Automatically discovers application dependencies
• Creates comprehensive service maps
• Shows real-time health status

CI Class Manager

• Manage CI classes and attributes
• Define identification and reconciliation rules
• Control CI class hierarchy

Identification and Reconciliation

• Identify unique CIs during discovery
• Reconcile differences between data sources
• Prevent duplicate CI creation

Conclusion

The CMDB is the foundation of effective IT Service Management in ServiceNow. Understanding Configuration Items, their relationships, and lifecycle management is crucial for CSA certification and real-world success.

Key Takeaways:

• CMDB is the central repository for all IT components
• CIs are any components needed to deliver IT services
• CI relationships show dependencies and impacts
• Proper CMDB management improves incident, change, and service management

Master these CMDB concepts, and you'll be well-prepared for both your CSA exam and practical ServiceNow administration.

Related Topics

• Service Mapping and Dependency Views
• Asset Management Integration
• ServiceNow Discovery
• Change Management Impact Analysis

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Test your CMDB knowledge with our practice questions in the Tests section.