{:node-list
   [["g1-node-1" "group-1" "10.0.0.1" :debian :os-version "6.0.1"]
    ["g1-node-2" "group-1" "10.0.0.2" :debian :os-version "6.0.1"]
    ["g2-node-1" "group-2" "192.168.0.1" :centos :os-version "5.3"]
    ["g2-node-2" "group-2" "192.168.0.2" :centos :os-version "5.3"]
    ["g2-node-3" "group-2" "192.168.0.3" :centos :os-version "5.3"]] ...}