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5.5.4. What-if scenarios

You can make changes to the saved or shadow CIB and simulate it again, to see how Pacemaker would react differently. You can edit the XML by hand, use command-line tools such as cibadmin with either a shadow CIB or the CIB_file environment variable set to the filename, or use higher-level tool support (see the man pages of the specific tool you’re using for how to perform actions on a saved CIB file rather than the live CIB).
You can also inject node failures and/or action failures into the simulation; see the crm_simulate man page for more details.
This capability is useful when using a shadow CIB to edit the configuration. Before committing the changes to the live cluster with crm_shadow --commit, you can use crm_simulate to see how the cluster will react to the changes.