This package contains several nagios plugins for monitoring Linux boxes. Nagios is an open source computer system monitoring, network monitoring and infrastructure monitoring software application (see: http://www.nagios.org/).

Here is the list of the available plugins:

• check_clock - returns the number of seconds elapsed between local time and Nagios server time
• check_cpu - checks the CPU (user mode) utilization
• check_cpufreq - displays the CPU frequency characteristics
• check_cswch - checks the total number of context switches across all CPUs
• check_fc - monitors the status of the fiber status ports
• check_ifmountfs - checks whether the given filesystems are mounted
• check_intr - monitors the total number of system interrupts
• check_iowait - monitors the I/O wait bottlenecks
• check_load - checks the current system load average
• check_memory - checks the memory usage
• check_multipath - checks the multipath topology status
• check_nbprocs - displays the number of running processes per user
• check_network - displays some network interfaces statistics
• check_paging - checks the memory and swap paging
• check_readonlyfs - checks for readonly filesystems
• check_swap - checks the swap usage
• check_tcpcount - checks the tcp network usage
• check_temperature - monitors the hardware's temperature
• check_uptime - checks how long the system has been running
• check_users - displays the number of users that are currently logged on

The full documentation of the nagios-plugins-linux is available online here or in the GitHub wiki page.

The source code of the latest stable version can be found in this page.

The check_clock plugin

This Nagios plugin returns the number of seconds elapsed between the host local time and Nagios time.

Usage

check_clock [-w COUNTER] [-c COUNTER] --refclock TIME
check_clock --help

Command line options

• -r, --refclock TIME: the clock reference (in seconds since the Epoch)
• -w, --warning COUNTER: warning threshold
• -v, --verbose: show details for command-line debugging (Nagios may truncate output)
• -c, --critical COUNTER: critical threshold
• -h, --help: display this help and exit
• -V, --version: output version information and exit

Examples

# $ARG1$ is the number of seconds since the Epoch --
# "$(date '+%s')" -- provided by the Nagios poller
check_clock -w 60 -c 120 --refclock $ARG1$

The check_cpu plugin

This Nagios plugin checks the CPU (user mode) utilization.

Usage

check_cpu [-m] [-p] [-v] [-w PERC] [-c PERC] [delay [count]]
check_cpu --cpuinfo
check_cpu --help

Command line options

• -m, --no-cpu-model: do not display the cpu model in the output message
• -p, --per-cpu: display the utilization of each CPU
• -w, --warning PERCENT: warning threshold
• -c, --critical PERCENT: critical threshold
• -v, --verbose: show details for command-line debugging (Nagios may truncate output)
• -i, --cpuinfo: show the CPU characteristics (for debugging)
• -h, --help: display this help and exit
• -V, --version: output version information and exit
• delay is the delay between updates in seconds (default: 1sec)
• count is the number of updates (default: 2)

Examples

check_cpu -w 85% -c 95%
cpu (CPU: Intel(R) Atom(TM) CPU N270 @ 1.60GHz) OK - cpu user 79.5% | cpu_user=79.5% cpu_system=20.5% cpu_idle=0.0% cpu_iowait=0.0% cpu_steal=0.0%

# count = 1 means the percentages of total CPU time from boottime
check_cpu -m -w 85% -c 95% 1 1
cpu OK - cpu user 33.2% | cpu_user=33.2% cpu_system=6.5% cpu_idle=57.1% cpu_iowait=3.2% cpu_steal=0.0%

check_cpu -m -p -w 85% -c 95% 1 2
cpu OK - cpu user 20.6% | cpu_user=20.2% cpu_system=6.7% cpu_idle=66.8% cpu_iowait=6.2% cpu_steal=0.0% cpu0_user=20.8% cpu0_system=7.3% cpu0_idle=59.4% cpu0_iowait=12.5% cpu0_steal=0.0% cpu1_user=20.6% cpu1_system=5.2% cpu1_idle=74.2% cpu1_iowait=0.0% cpu1_steal=0.0%

The check_cpufreq plugin

This Nagios plugin displays the CPU frequency characteristics.

Usage

check_cpufreq [-m] [-w COUNTER] -c [COUNTER]
check_cpufreq --help

Command line options

• -m, --no-cpu-model: do not display the cpu model in the output message
• -w, --warning PERCENT: warning threshold
• -c, --critical PERCENT: critical threshold
• -h, --help: display this help and exit
• -V, --version: output version information and exit

Examples

check_cpufreq -m -w 800000:

The check_cswch plugin

This Nagios plugin checks the total number of context switches across all CPUs.

Usage

check_cswch [-v] [-w COUNTER] -c [COUNTER] [delay [count]]
check_cswch --help

Command line options

• -w, --warning COUNTER: warning threshold
• -c, --critical COUNTER: critical threshold
• -v, --verbose: show details for command-line debugging (Nagios may truncate output)
• -h, --help: display this help and exit
• -V, --version: output version information and exit

Examples

check_cswch 1 2

The check_fc plugin

This Nagios plugin monitors the status of the fiber status ports.

Usage

check_fc [-w COUNTER] -c [COUNTER] [delay [count]]
check_fc -i [-v]
check_fc --help

Command line options

• -w, --warning COUNTER: warning threshold
• -c, --critical COUNTER: critical threshold
• -v, --verbose: show details for command-line debugging (Nagios may truncate output)
• -h, --help: display this help and exit
• -V, --version: output version information and exit

Examples

check_fc -c 2:
check_fc -i -v

The check_ifmountfs plugin

This Nagios plugin checks whether the given filesystems are mounted.

Usage

check_ifmountfs [FILESYSTEM]...
check_ifmountfs --help

Examples

check_ifmountfs /mnt/nfs-data /mnt/cdrom

The check_intr plugin

This Nagios plugin monitors the total number of system interrupts.

Usage

check_intr [-v] [-w COUNTER] -c [COUNTER] [delay [count]]
check_intr --help

Command line options

• -w, --warning COUNTER: warning threshold
• -c, --critical COUNTER: critical threshold
• -v, --verbose: show details for command-line debugging (Nagios may truncate output)
• -h, --help: display this help and exit
• -V, --version: output version information and exit

Examples

check_intr 1 2

The check_iowait plugin

This Nagios plugin checks for I/O wait bottlenecks.

Usage

check_iowait [-v] [-w PERC] [-c PERC] [delay [count]]
check_iowait --help

Command line options

• -w, --warning PERCENT: warning threshold
• -c, --critical PERCENT: critical threshold
• -v, --verbose: show details for command-line debugging (Nagios may truncate output)
• delay is the delay between updates in seconds (default: 1sec)
• count is the number of updates (default: 2)
• -h, --help: display this help and exit
• -V, --version: output version information and exit

Examples

check_iowait -w 10% -c 20%
iowait OK - cpu iowait 0% | cpu_user=31%, cpu_system=13%, cpu_idle=56%, cpu_iowait=0%, cpu_steal=0%

# count = 1 means the percentages of total CPU time from boottime
check_iowait -w 10% -c 20% 1 1
iowait OK - cpu iowait 7% | cpu_user=34%, cpu_system=11%, cpu_idle=49%, cpu_iowait=7%, cpu_steal=0%

The check_load plugin

This Nagios plugin tests the current system load average.

Usage

check_load [-r] [--load1=w,c] [--load5=w,c] [--load15=w,c]
check_load --help

Command line options

• -r, --percpu: divide the load averages by the number of CPUs
• 1, --load1=WLOAD1,CLOAD1: warning and critial thresholds for load1
• 5, --load5=WLOAD5,CLOAD5. warning and critical thresholds for load5
• L, --load15=WLOAD15,CLOAD15: warning and critical thresholds for load15
• -h, --help: display this help and exit
• -V, --version: output version information and exit

Examples

check_load -r --load1=2,3 --load15=1.5,2.5

The check_memory and check_swap plugins

These two nagios plugins respectivery check for memory and swap usage.

Usage

check_memory [-s] [-b,-k,-m,-g] [-w PERC] [-c PERC]
check_swap [-b,-k,-m,-g] [-w PERC] [-c PERC]

check_memory --help
check_swap --help

Command line options

• -a, --available: display the memory available (kernel 2.6.27+) / free (older kernels)
• -s, --vmstats: display the virtual memory perfdata
• -b,-k,-m,-g: show output in bytes, KB (the default), MB, or GB
• -w, --warning PERCENT: warning threshold
• -c, --critical PERCENT: critical threshold
• -h, --help: display this help and exit
• -V, --version: output version information and exit

Examples

check_memory --vmstats -w 80% -c 90%
memory OK: 26.05% (266580 kB) used | mem_total=1023312kB, mem_used=266580kB, mem_free=171548kB, mem_shared=51244kB, mem_buffers=34744kB, mem_cached=550440kB, mem_available=674712kB, mem_active=325136kB, mem_anonpages=240464kB, mem_committed=1704152kB, mem_dirty=604kB, mem_inactive=468904kB, vmem_pageins/s=128, vmem_pageouts/s=0, vmem_pgmajfault/s=0
  # mem_total    : Total usable physical RAM
  # mem_used     : Total amount of physical RAM used by the system
  # mem_free     : Amount of RAM that is currently unused
  # mem_shared   : Now always zero; not calculated
  # mem_buffers  : Amount of physical RAM used for file buffers
  # mem_cached   : In-memory cache for files read from the disk (the page cache)
  # mem_available: kernel >= 2.6.27: memory available for starting new applications, without swapping
  # mem_available: kernel < 2.6.27: same as 'mem_free'
  # mem_active   : Memory that has been used more recently
  # mem_anonpages: Non-file backed pages mapped into user-space page tables
  # mem_committed: The amount of memory presently allocated on the system
  # mem_dirty    : Memory which is waiting to get written back to the disk
  # mem_inactive : Memory which has been less recently used
  # vmem_pageins
  # vmem_pageouts: The number of memory pages the system has written in and out to disk
  # vmem_pgmajfault: The number of memory major pagefaults

check_memory -a -m -w 20%: -c 10%:
memory OK: 65.40% (653 MB) available | mem_total=999MB, mem_used=264MB, mem_free=105MB, mem_shared=50MB, mem_buffers=38MB, mem_cached=590MB, mem_available=653MB, mem_active=341MB, mem_anonpages=238MB, mem_committed=1663MB, mem_dirty=0MB, mem_inactive=495MB

check_swap -w 40% -c 60% -m
swap WARNING: 42.70% (895104 kB) used | swap_total=2096444kB, swap_used=895104kB, swap_free=1201340kB, swap_cached=117024kB, swap_pageins/s=97, swap_pageouts/s=73
  # swap_total   : Total amount of swap space available
  # swap_used    : Total amount of swap used by the system
  # swap_free    : Amount of swap space that is currently unused
  # swap_cached  : The amount of swap used as cache memory
  # swap_pageins 
  # swap_pageouts: The number of swap pages the system has brought in and out

The check_multipath plugin

This Nagios plugin checks the multipath topology status.

Usage

check_multipath [-v]
check_multipath --help

Command line options

• -v, --verbose: show details for command-line debugging (Nagios may truncate output)
• -h, --help: display this help and exit
• -V, --version: output version information and exit

Examples

check_multipath

The check_nbprocs plugin

This Nagios plugin displays the number of running processes per user.

Usage

check_nbprocs [--verbose] [--threads] [-w COUNT] [-c COUNT]
check_nbprocs --help

Command line options

• -t, --threads: display the number of threads
• -v, --verbose: show details for command-line debugging (Nagios may truncate output)
• -h, --help: display this help and exit
• -V, --version: output version information and exit

Examples

check_nbprocs
check_nbprocs --threads -w 1500 -c 2000

The check_network plugin

This Nagios plugin checks displays some network interfaces.statistics.

Usage

check_network
check_network --help

Command line options

• -h, --help: display this help and exit
• -V, --version: output version information and exit

The check_paging plugin

This Nagios plugin checks for memory and swap paging.

Usage

check_paging [--paging] [--swapping]
check_paging --help

Command line options

• -p, --paging: display the page reads and writes
• -s, --swapping: display the swap reads amd writes
• -h, --help: display this help and exit
• -V, --version: output version information and exit

Examples

check_paging --paging --swapping -w 10 -c 25

The check_readonlyfs plugin

This Nagios plugin checks for readonly filesystems.

Usage

check_readonlyfs [OPTION]... [FILE]...
check_readonlyfs --help

Command line options

• -l, --local: limit listing to local file systems
• -L, --list: display the list of checked file systems
• -T, --type=TYPE: limit listing to file systems of type TYPE
• -X, --exclude-type=TYPE: limit listing to file systems not of type TYPE
• -h, --help: display this help and exit
• -V, --version: output version information and exit

Examples

check_readonlyfs
check_readonlyfs -l -T ext3 -T ext4
check_readonlyfs -l -X vfat

The check_tcpcount plugin

This plugin displays TCP network and socket informations.

Usage

check_tcpcount [--tcp] [--tcp6] --warning COUNTER --critical COUNTER
check_tcpcount --help

Command line options

• -t, --tcp: display the statistics for the TCP protocol (the default)
• -6, --tcp6: display the statistics for the TCPv6 protocol
• -h, --help: display this help and exit
• -V, --version: output version information and exit

Examples

check_tcpcount -w 1000 -c 1500
check_tcpcount --tcp6 -w 1000 -c 1500
check_tcpcount --tcp --tcp6 -w 1500 -c 2000

The check_temperature plugin

This Nagios plugin monitors the hardware's temperature.

Usage

check_temperature [-f|-k] [-t <thermal_zone>] [-w COUNTER] [-c COUNTER]
check_temperature -.help

Command line options

• -f, --fahrenheit: use fahrenheit as the temperature unit
• -k, --kelvin: use kelvin as the temperature unit
• -t, --thermal_zone: only consider a specific thermal zone
• -w, --warning COUNTER: warning threshold
• -c, --critical COUNTER: critical threshold
• -h, --help: display this help and exit
• -V, --version: output version information and exit

Examples

check_temperature -w 80 -c 90
check_temperature -t thermal_zone0 -w 80 -c 90

The check_uptime plugin

This Nagios plugin checks how long the system has been running.

Usage

check_uptime [-m] [--warning [@]start:end] [--critical [@]start:end]
check_uptime --help

Command line options

• -m, --clock-monotonic use the monotonic clock for retrieving the time
• -w, --warning COUNTER: warning threshold
• -c, --critical COUNTER: critical threshold
• -h, --help: display this help and exit
• -V, --version: output version information and exit

and

• start <= end
• start and ":" is not required if start=0
• if range is of format "start:" and end is not specified, assume end is infinity
• to specify negative infinity, use "~"
• alert is raised if metric is outside start and end range (inclusive of endpoints)
• if range starts with "@", then alert if inside this range (inclusive of endpoints)

Examples

check_uptime
check_uptime --warning 30: --critical 15:
check_uptime --clock-monotonic -c 15: -w 30:

The check_users plugin

This Nagios plugin displays the number of users that are currently logged on.

Usage

check_users [-w PERC] [-c PERC]

Command line options

• -w, --warning PERCENT: warning threshold
• -c, --critical PERCENT: critical threshold
• -v, --verbose: show details for command-line debugging (Nagios may truncate output)
• -h, --help: display this help and exit
• -V, --version: output version information and exit

Examples

check_users -w 1

This package uses GNU autotools for configuration and installation.

If you have cloned the git repository then you will need to run autoreconf --install to generate the required files.

Run ./configure --help to see a list of available install options. The plugin will be installed by default into LIBEXECDIR.

It is highly likely that you will want to customise this location to suit your needs, i.e.:

    ./configure --libexecdir=/usr/lib/nagios/plugins

After ./configure has completed successfully run make install and you're done!

This package is written in plain C, making as few assumptions as possible, and sticking closely to ANSI C/POSIX. A C99-compliant compiler is required anyway.

This package is known to compile with:

• gcc 4.1.2 (RHEL 5 / CentOS 5),
• gcc 4.4 (RHEL6 / CentOS 6),
• gcc 4.8.2 (RHEL7 / CentOS 7),
• gcc 5.1.1 20150618, 5.3.1 20151207, clang 3.7.0 (Fedora 23 Cloud),
• gcc 4.9.0-4.9.2, 5.2.0, 5.3.0, clang 3.1 and 3.5.1 (openmamba GNU/Linux 2.90+).

List of the Linux kernels that have been successfully tested:

• 2.6.18, 2.6.32,
• 3.10, 3.14, 3.18,
• 4.2.5, 4.2.8.

If you find a bug please create an issue in the project bug tracker at github