cibadmin

cibadmin is a command-line utility used to manage the Cluster Information Base (CIB) in Pacemaker-based high-availability clusters. The CIB is a central XML-based database that stores the complete configuration and current state of the cluster, including nodes, resources, constraints, and other configuration parameters.

Purpose

• Configuration Management: cibadmin allows administrators to view, edit, and update the cluster configuration stored in the CIB. This is critical for applying new settings, modifying resources, or changing constraints.

• Backup and Restore: The tool can be used to export the current CIB configuration to a file, making it possible to back up the configuration or compare changes over time. It also allows for restoring a previously saved CIB.

• Diagnostics and Troubleshooting: By dumping the CIB content, administrators can review the exact configuration that the cluster manager is using, which aids in troubleshooting configuration-related issues.

Basic Syntax

cibadmin [options]

cibadmin supports various options for querying, modifying, and saving the CIB configuration.

Common Options and Usage

• Dump the Current CIB Configuration:

  cibadmin --query

  This command outputs the entire CIB configuration in XML format, allowing you to review all current cluster settings.

• Export the CIB to a File:

  cibadmin --query > /path/to/backup-cib.xml

  This exports the current configuration to a file for backup or further analysis.

• Load a New CIB Configuration:

  cibadmin --replace --xml-text="$(cat /path/to/new-cib.xml)"

  This command replaces the current CIB with the contents of the specified XML file. Warning: Modifying the CIB can impact cluster behavior. Always back up the current CIB before making changes.

• Validate the CIB Configuration: Some versions of cibadmin may support options to check the syntax and consistency of the configuration before applying it, reducing the risk of errors.

• Help and Version:

  cibadmin --help
  cibadmin --version

Example Workflow

1. Backup the Current CIB:

   cibadmin --query > /root/backup-cib.xml

   This creates a backup file of the current cluster configuration.

2. Review or Edit the CIB: Open the backup file in your preferred XML editor to review or modify the configuration as needed.

3. Apply a New Configuration:

   cibadmin --replace --xml-text="$(cat /root/new-cib.xml)"

   Replace the current CIB with your new configuration. Be cautious with this operation, as errors in the configuration may cause resource disruption.

Best Practices

• Always Backup First: Before making any changes to the CIB, use cibadmin --query to back up the current configuration.

• Test Changes in a Staging Environment: If possible, validate configuration changes in a test environment or use simulation tools (like crm_simulate) to ensure that the new settings behave as expected.

• Validate XML Syntax: Since the CIB is XML-based, ensure that any modifications result in valid XML. This helps prevent parsing errors when the configuration is applied.

• Use Version Control: Consider storing your CIB backups and configuration files in version control to track changes over time and quickly revert if needed.

Conclusion

cibadmin is an essential tool for managing the configuration of Pacemaker clusters. It provides the ability to query, back up, modify, and restore the Cluster Information Base, making it a critical component for cluster administrators. With careful use and adherence to best practices, cibadmin enables safe and effective management of cluster configurations, contributing to the overall stability and high availability of critical systems.