Applies to SUSE Linux Enterprise High Availability 15 SP3

C Cluster management tools (command line) #

SUSE Linux Enterprise High Availability ships with a comprehensive set of tools to assists you in managing your cluster from the command line. This chapter introduces the tools needed for managing the cluster configuration in the CIB and the cluster resources. Other command line tools for managing resource agents or tools used for debugging (and troubleshooting) your setup are covered in Appendix A, Troubleshooting.

Note: Use crmsh

This tool is for experts only. Usually the crm shell (crmsh) is the recommended way of managing your cluster.

The following list presents several tasks related to cluster management and briefly introduces the tools to use to accomplish these tasks:

Monitoring the cluster's status: The crm_mon command allows you to monitor your cluster's status and configuration. Its output includes the number of nodes, uname, UUID, status, the resources configured in your cluster, and the current status of each. The output of crm_mon can be displayed at the console or printed into an HTML file. When provided with a cluster configuration file without the status section, crm_mon creates an overview of nodes and resources as specified in the file. See the crm_mon man page for a detailed introduction to this tool's usage and command syntax.
Managing the CIB: The cibadmin command is the low-level administrative command for manipulating the CIB. It can be used to dump all or part of the CIB, update all or part of it, modify all or part of it, delete the entire CIB, or perform miscellaneous CIB administrative operations. See the cibadmin man page for a detailed introduction to this tool's usage and command syntax.
Managing configuration changes: The crm_diff command assists you in creating and applying XML patches. This can be useful for visualizing the changes between two versions of the cluster configuration or saving changes so they can be applied at a later time using cibadmin. See the crm_diff man page for a detailed introduction to this tool's usage and command syntax.
Manipulating CIB attributes: The crm_attribute command lets you query and manipulate node attributes and cluster configuration options that are used in the CIB. See the crm_attribute man page for a detailed introduction to this tool's usage and command syntax.
Validating the cluster configuration: The crm_verify command checks the configuration database (CIB) for consistency and other problems. It can check a file containing the configuration or connect to a running cluster. It reports two classes of problems. Errors must be fixed before the High Availability software can work properly while warning resolution is up to the administrator. crm_verify assists in creating new or modified configurations. You can take a local copy of a CIB in the running cluster, edit it, validate it using crm_verify, then put the new configuration into effect using cibadmin. See the crm_verify man page for a detailed introduction to this tool's usage and command syntax.
Managing resource configurations: The crm_resource command performs various resource-related actions on the cluster. It lets you modify the definition of configured resources, start and stop resources, or delete and migrate resources between nodes. See the crm_resource man page for a detailed introduction to this tool's usage and command syntax.
Managing resource fail counts: The crm_failcount command queries the number of failures per resource on a given node. This tool can also be used to reset the fail count, allowing the resource to again run on nodes where it had failed too often. See the crm_failcount man page for a detailed introduction to this tool's usage and command syntax.
Managing a node's standby status: The crm_standby command can manipulate a node's standby attribute. Any node in standby mode is no longer eligible to host resources and any resources that are there must be moved. Standby mode can be useful for performing maintenance tasks, such as Kernel updates. Remove the standby attribute from the node for it to become a fully active member of the cluster again. See the crm_standby man page for a detailed introduction to this tool's usage and command syntax.