Hi Got a group of 16 VMs - running OLE 6.8, and xymon 4.3.28 - which are an exact replica. About a month ago, one of those stopped to produce the rrd graph for CPU utilisation. a dump of the rrd file showed null values since certain stage. I deleted the vmstat rrd file and killed the rrd processes - still no graph. checked the client log to verify that the vmstat is coming in - they do. any idea how to solve it? cheers Ron