this one is really just a stupid bash trick. all it will do is display the current swap usage as a bar graph. and there is more formatting then there is calculation.
sometimes you need to run a command on ALL of a type of node in openstack, and if you have miantirs openstack you have a fuel server you can run these commands from. using this quick one liner for example will restart every nova-compute process on all up and active nodes.
Quick command to see how many tapes are in Each media pool in Netbackup.