Originally Posted by hemasak
Hi, We have configured some server monitoring parameters in Nagios and for one parameter 'CPU Usage', it is showing in Orange color and the status is showing as 'Unknown'. While clicking on the CPU Usage, it is showing as "NRPE: Unable to read output". Please let me know how to solve this.
Read the "Question Guidelines" link in my posting signature. You have provided no useful details that would let anyone help you...just saying "some server monitoring parameters" tells us nothing. You don't say what version/distro of Linux you're using, version of Nagios, how you configured it, if this was EVER working or if this is a new issue, and anything you've done/tried so far. We don't know anything about your configuration, see any of the files, etc. In short...with no information, we can't answer any questions.
And did you try looking this up first? Putting the exact error into Google pulls up lots of potential solutions.