NAME

cpu - Plugin to monitor CPU usage.

APPLICABLE SYSTEMS

All Linux systems

CONFIGURATION

The following is default configuration

  [cpu]
        env.HZ  100

See "BUGS" for a explanation of this setting.

EXAMPLE WARNING AND CRITICAL SETTINGS

You can also set warning and critical levels for each of the data series the plugin reports. The following environment variables are used as default for all fields:

  env.warning
  env.critical

But each field can be controlled separately:

  env.system_warning
  env.system_critical

  env.user_warning
  env.user_critical

  env.nice_warning
  env.nice_critical

  env.idle_warning
  env.idle_critical

For some kernels there is also the following settings:

  env.iowait_warning
  env.iowait_critical
  env.irq_warning
  env.irq_critical
  env.softirq_warning
  env.softirq_critical
  env.steal_warning
  env.steal_critical
  env.guest_warning
  env.guest_critical

INTERPRETATION

The plugin shows cpu usage in percent. In case of more than one core it displays 100% for each core.

If a core is 100% busy there will be no "iowait" showing, that only shows if the CPU has nothing else to do while it waits on IO. Therefore a 100% busy core can hide a lot of iowait. Please refer to the IO latency and other disk related graphs for further information about IO performance.

MAGIC MARKERS

  #%# family=auto
  #%# capabilities=autoconf

VERSION

  $Id$

BUGS

Some combinations of hardware and Linux (probably only 2.4 kernels) use 1000 units/second in /proc/stat corresponding to the systems HZ. (see /usr/src/linux/include/asm/param.h). But Almost all systems use 100 units/second and this is our default. Even if Documentation/proc.txt in the kernel source says otherwise. - Finding and fix by dz@426.ch

Otherwise none known

AUTHOR

Unknown

LICENSE

GPLv2