Usage: plabstats [-dfh] [-CDHILMS]
  -d    print debug diagnostics
  -f    fetch new data, else use what is in /tmp/plabxml
  -h    this help message
  -i    print IP address along with metrics
  -n    do not print hostname with metrics

  -C    print Ganglia CPU metrics, sorted by %CPU usage
  -D    print Ganglia disk metrics, sorted by %disk usage
  -L    print Ganglia load metrics, sorted by one minute load
  -M    print Ganglia memory metrics, sorted by %mem usage
  -S    print Emulab state info, summarizing per-node availability

Default is to print a terse summary of per-node resource usage.
Use "plabstats -f" to get fresh data or try something whacky like:
	plabstats -S | grep accept_3
to get the list of nodes which are currently available for mapping
by a "level 3" (aka, average) resource consuming experiment, or:
	plabstats -S | grep reject
to get info about the nodes that cannot be used along with the reason(s) why.

Needs some refinement:
  plabmetrics should store raw info into the DB where plabstats can get it
  presentation of Emulab state info should be improved