Also I'd recommend kanif:

http://taktuk.gforge.inria.fr/kanif/

This is a great tool to do mass changes to our 1200 CPU compute cluster. The best part about this is, it will map all of the hosts with the same output together and reduce this down to just one instance of the output, with the affected hostnames listed together. So instead of 500 instances of the same output data I get one. This comes in handy for finding hosts which are different than what I'm looking for.

Simple example:

  --------------------------------------------------------------------------------
  compute[0009,0051,0187] (3 HOSTS)
  --------------------------------------------------------------------------------
  Filesystem            Size  Used Avail Use% Mounted on
  /dev/mapper/rootvg-rootlv
                         58G   14G   42G  25% /
  --------------------------------------------------------------------------------
  compute[0013,0038,0044,0046,0065,0103,0125,0142,0195,0213,0216,0234] (12 HOSTS)
  --------------------------------------------------------------------------------
  Filesystem            Size  Used Avail Use% Mounted on
  /dev/mapper/rootvg-rootlv
                         58G   11G   44G  19% /
  --------------------------------------------------------------------------------
    compute0247 (1 HOST)
  --------------------------------------------------------------------------------
  Filesystem            Size  Used Avail Use% Mounted on
  /dev/mapper/rootvg-rootlv
                       58G  7.6G   47G  15% /