OS-Based User Defined Metric

Hi there,

i have created an o/s based UDM which returnss a "df" percent used column back to oem.  for some reason i get collection failure even though oem is registering the message.. here is the details from the "collection failure" link in oem.  any ideas how to run a script which echo's a value back to oem as a metric?

thanks!

Target		marsdev
	Type		Host
	Metric		User Defined Metrics: Nfs_oraexp_fit_Percent_Full
	Collection Timestamp		Jul 22, 2011 8:45:58 AM
	Error Type		Collection Failure
	Message		80