Visualizing Pacemaker resource constraints

If a picture is worth a thousand words, then code that generates pictures from words is worth…uh, anyway, I wrote a script that produces dot output from Pacemaker start and colocation constraints: https://github.com/larsks/pacemaker-tools/ You can pass this output to graphviz to create visualizations of your Pacemaker resource constraints. The graph-constraints.py script in that repository consumes the output of cibadmin -Q and can produce output for either start constraints (-S, the default) or colocation constraints (-C).
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Stupid Pacemaker XML tricks

I’ve recently spent some time working with Pacemaker, and ended up with an interesting collection of XPath snippets that I am publishing here for your use and/or amusement. Check if there are any inactive resources pcs status xml | xmllint –xpath ‘//resource[@active="false"]’ - >&/dev/null && echo "There are inactive resources" This selects any resource (//resource) in the output of pcs status xml that has the attribute active set to false. If there are no matches to this query, xmllint exits with an error code.
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