Linux Networking Cookbook

14.8. Monitoring CPU User and Idle Times

Problem

The previous recipe gives a useful snapshot of CPU activity over time, but you would like to see separate rather than aggregate values, such as idle time and user processes, or system and user processes, or perhaps one of these alone.

Solution

Try adding this to mrtg.cfg:

	# monitor CPU user and idle loads
	#
	Target[xena2.cpu]: ssCpuRawUser.0&ssCpuRawIdle.0:password@localhost
	RouterUptime[xena2.cpu]: password@localhost
	MaxBytes[xena2.cpu]: 100
	Title[xena2.cpu]: User and Idle CPU usage- Xena
	PageTop[xena2.cpu]: <H1>User and CPU Load- Xena</H1>
	ShortLegend[xena2.cpu]: %
	YLegend[xena2.cpu]: CPU Usage
	Legend1[xena2.cpu]: User CPU in % (Load)
	Legend2[xena2.cpu]: Idle CPU in % (Load)
	LegendI[xena2.cpu]: User
	LegendO[xena2.cpu]: Idle
	Options[xena2.cpu]: growright,nopercent
	Unscaled[xena2.cpu]: ymwd

Make sure that LoadMIBs: /usr/local/share/snmp/mibs/UCD-SNMP-MIB.txt is in the Global Config Options section. Run these commands to load the changes:

	# env LANG=C mrtg /etc/mrtg.cfg
	# indexmaker --output=/var/www/mrtg/index.html /etc/mrtg.cfg

Mind your filepaths because they vary on different Linux distributions, and remember to run the first command until it quits emitting error messages, which should take no more than three tries.

So, point your web browser to localhost (http://localhost/mrtg), and admire your new graphs, which are now tracking two values:

	     Max    Average  Current
	User 9.0 %    8.0 %   6.0 %
	Idle 92.0 %  79.0 %  93.0 %

Discussion

There are two important ...