openstack_backup.rb

require 'mcollective'

include MCollective::RPC

c = rpcclient("rpcutil")
c.discovery_method="mc"

all_nodes = c.discover.clone

all_nodes.in_groups_of(5) do |nodes|
  c.reset
  c.discover :nodes => nodes.compact

  resp = c.freenodes

  # check responses are all ok etc
  # kick off backups etc

  c.unfreeze

end