Search Exchange

Search All Sites

Nagios Live Webinars

Let our experts show you how Nagios can help your organization.

Contact Us

Phone: 1-888-NAGIOS-1


Remember Me

check_linux_stats Featured Popular

Network Monitoring Software - Download Nagios XI
Log Management Software - Nagios Log Server - Download
Netflow Analysis Software - Nagios Network Analyzer - Download
75 votes
Current Version
Last Release Date
Compatible With
  • Nagios 2.x
  • Nagios 3.x
  • Nagios 4.x
  • Nagios XI
Plugin to check linux system performance (cpu, mem, load, disk usage, disk io, network usage, open files and processes).
A perl plugin using Sys::Statistics::Linux

Thanks to Jonny Schulz, the author of Sys::Statistics::Linux, for his great work ( !

v1.2 Changelog :
- Add Paging statistics
- Add swapused and active memory on perfparse statistics
- Remove unused -H option (mthuijs)
v1.3 Changelog :
- Add uptime check, warning threshold in minutes (csterley)
- Replace /usr/local/nagios/libexec with FindBin (eulen)
- Fix reports network traffic in bytes (dbsanders)
v1.4 Changelog :
- Illegal division by zero (helium_rday, RedFish)
- Get the cache out of the used memory (waterdeep, dbsanders)
- Removed unused $return_str on check io disk (RedFish)
- Add steal cpu statistics
v1.5 Changelog :
- Add paging statistics to check for major faults (
- bug, when using unit=MB for disk usage, the perf data writtens only KB (john12)
- Bug, multiple pipe on IO perfcournter (ledistordu)
- Add CPU context switch statistics
Usage :
-h, --help
print this help message
-C, --cpu
check cpu usage
-P, --proc
check the processes number
-M, --memory
check memory usage (memory used, swap used and memory cached)
-N, --network=NETWORK USAGE
check network usage in resq or bytes (default bytes)
-D, --disk=DISK USAGE
check disk usage
check disk I/O (r/w on /dev/sd*)
check load average
-F, --file=FILE STATS
check open files (file alloc, inode alloc)
-S, --socket=SOCKET STATS
socket usage (tcp, udp, raw)
check CPU context switch
-U, --uptime
-p, --pattern
-w, --warning
warning thresold
-c, --critical
critical thresold
-s, --sleep
default 1 sec.
-u, --unit
%, KB, MB or GB left on disk usage, default : MB
REQS OR BYTES on disk io statistics, default : REQS
-V, --version
version number

ex :
* Cpu usage :
./ -C -w 90 -c 100 -s 5
CPU OK : idle 99.80% | user=0.00% system=0.20% iowait=0.00% idle=99.80%;90;100

* Load average :
./ -L -w 10,8,5 -c 20,18,15
LOAD AVERAGE OK : 0.20,0.07,0.16 | load1=0.20;10;20;0 load5=0.07;8;18;0 load15=0.16;5;15;0

* Memory usage :
./ -M -w 99,50 -c 100,50
MEMORY OK : Mem used=92.57%, Swap used=0.01% |MemUsed=92.57%;95;99 SwapUsed=0.01;50;50 MemCached=12.62 SwapCached=0.00 Active=12.61

* Disk usage :
./ -D -w 10 -c 5 -p /,/usr,/tmp,/var
DISK WARNING used : / 3331.80MB on 3875.09MB (8.86% free) /usr 10084.27MB on 14528.41MB (25.43% free)| /=3331.80MB /usr=10084.27MB

* Disk I/O :
./ -I -w 100,70 -c 150,100 -p sda1,sda2,sda4
DISK I/O OK | sda2_read=0.00;100;150 sda2_write=0.00;70;100 sda4_read=0.00;100;150 sda4_write=0.00;70;100 sda1_read=0.00;100;150 sda1_write=0.00;70;100

* Network usage :
./ -N -w 30000 -c 45000 -p eth0
NET USAGE OK eth0:8021.78KB | eth0_txbyt=3461.39KB eth0_txerrs=0.00KB eth0_rxbyt=4560.40KB eth0_rxerrs=0.00KB

* Open files :
./ -F -w 10000,150000 -c 15000,250000
OPEN FILES OK allocated: 1728 (inodes: 70390) | fhalloc=1728;10000;15000;411810 inalloc=70390;150000;250000;100250 dentries=50754

* Socket usage :
./ -S -w 1000 -c 2000
SOCKET USAGE OK : used 257 |used=257;1000;2000 tcp=18 udp=5 raw=0

* Number of procs :
./ -P -w 1000 -c 2000
PROCS OK : count 272 |count=272;1000;2000 runqueue=2 blocked=0 running=2 new=0.98

* Process mem & cpu :
./ -T -w 2000000000 -c 3000000000 -p /var/run/
PROCESSES OK | java_vsize=1804918784;2000000000;3000000000 java_nswap=0 java_cnswap=0 java_cpu=0

* Paging statistics :
./ -W -w 10,1000,1 -c 20,2000,20 -s 3
Paging OK : in:0.00,out:0.00,flt:0.00 |pgpgin=0.00;10;20;0 pgpgout=0.00;1000;2000;0 pgmajfault=0.00;1;20;0 pswpin=0.00 pswpout=0.00

* Cpu context switch :
./ -X -w 6000 -c 70000 -s 2
CONTEXT SWITCH OK : context 80|ctxt=80

* Uptime :
./ -U -w 9
WARNING : up 0 days, 00:08:16 |uptime=496.05

Reviews (45)
Congratulations for the plugin. I like a lot, but it seems to have problems to execute NRPE, as when I run this plugin with NRPE it is unable to read the output. I have seen that other people have the same error. Could you help us to execute this plugin in remote? I have configured it, but it doen't work.
The plugins is great.. working with everything really fine but while i am using the unit variable with MB for Network Usages then its showing the default KB value.
Works great!
bymhoogveld, April 16, 2016
I really like this plugin and have written an extension which I'd like to send to you.
However, I can't seem to reach the owner by email at
I get a "550 5.2.1 This mailbox has been blocked due to inactivity" error message.
How can the owner be reached?
Hi!,This plugin is great i can do a lot of things with only one command,thanks to the developer.

In the shell all works fine,but i can't show it in the WEB-GUI(Of course before that I added the plugin to the nrpe.cfg and reload the nagios service.)

Whats is the problem here?

Thanks a lot for your support.
byBarreto, January 27, 2016
Check CPU is presenting problem, does anyone know what they have to modify the script?

/usr/lib64/nagios/plugins/ -C -w 90 -c 95
CPU OK : idle 99.50% |idle=99.50%;90;95 user=0.00% system=0.00% iowait=0.50% steal=0.00%check_linux_stats v1.5
Usage: /usr/lib64/nagios/plugins/ -C|-P|-M|-N|-D|-I|-L|-F|-S|-W|-U -p -w -c [-s ] [-u ] [-V] [-h]
-h, --help
print this help message
-C, --cpu=CPU USAGE
-P, --procs
-M, --memory=MEMORY USAGE
-N, --network=NETWORK USAGE
-D, --disk=DISK USAGE
-F, --file=FILE STATS
-S, --socket=SOCKET STATS
-U, --uptime
-p, --pattern
-w, --warning
-c, --critical
-s, --sleep
-u, --unit
%, KB, MB or GB left on disk usage, default : MB
REQS OR BYTES on disk io statistics, default : REQS
-V, --version
version number

ex :
Memory usage : perl -M -w 90 -c 95
Cpu usage : perl -C -w 90 -c 95 -s 5
Disk usage : perl -D -w 95 -c 100 -u % -p /tmp,/usr,/var
Load average : perl -L -w 10,8,5 -c 20,18,15
Paging statistics : perl -W -w 10,1000,1 -c 20,2000,20 -s 3
Process statistics : perl -P -w 100 -c 200
I/O statistics on disk device : perl -I -w 10 -c 5 -p sda1,sda4,sda5,sda6
Network usage : perl -N -w 10000 -c 100000000 -p eth0
Processes virtual memory : perl -T -w 9551820 -c 9551890 -p /var/run/
Cpu context switch : perl -X -w 6000 -c 70000 -s 2
Uptime : perl -U -w 5
byfritsspits, January 11, 2016
1 of 1 people found this review helpful

There's a small bug in v1.5 on line 62:

"if" should be "elsif" otherwise the -C (check_cpu) option will always show help.

Here's the diff:

--- /usr/lib/nagios/plugins/ 2016-01-12 11:51:20.586228411 +0100
+++ /usr/lib/nagios/plugins/ 2016-01-12 11:49:45.223925210 +0100
@@ -59,7 +59,7 @@
Owner's reply

I fixed this ugly bug..

great check.
I've found a little bug using hte CPU count.
It show me , on the perfdata, the entire help screen, just after the steal percentage:

[root@ph742502]/usr/local/nagios/libexec# ./ -C -w 70 -c 100 -s 2
CPU OK : idle 91.85 |idle=91.85%;70;100 user=0.59% system=0.34% iowait=7.12% steal=0.00%check_linux_stats v1.5
Usage: ./ -C|-P|-M|-N|-D|-I|-L|-F|-S|-W|-U -p -w -c [-s ] [-u ] [-V] [-h]
-h, --help
print this help message
-C, --cpu=CPU USAGE
-P, --procs
-M, --memory=MEMORY USAGE

Could be possible to solve?
i was not able to find it on the check_cpu section, it looks ok to me (but i'm not a programmer).

Thank you.

Owner's reply

I fixed this ugly bug..

byjframeau, January 6, 2016
1 of 1 people found this review helpful
Very good plugin.

Last version 1.5
check_cpu should be followed by a elsif.

--- 2016-01-06 22:06:17.000000000 +0100
+++ 2016-01-06 22:03:33.582324204 +0100
@@ -59,7 +59,7 @@

Owner's reply

I fixed this ugly bug.., September 11, 2015
1 of 1 people found this review helpful
Nice plugin. I added a check to paging statistics to check for major faults. diff follows.

--- 2015-09-11 12:22:42.977785368 -0500
+++ 2015-08-21 09:11:02.000000000 -0500
@@ -533,22 +533,21 @@
if(defined($stat->pgswstats)) {
$status = "OK";
my $page = $stat->pgswstats;
- my ($warn_in,$warn_out,$warn_flt) = split(/,/,$o_warning);
- my ($crit_in,$crit_out,$crit_flt) = split(/,/,$o_critical);
- if((($page->{pgpgin}>=$crit_in)&&($page->{pgpgout}>=$crit_out))||($page->{pgmajfault}>=$crit_flt)) {
+ my ($warn_in,$warn_out) = split(/,/,$o_warning);
+ my ($crit_in,$crit_out) = split(/,/,$o_critical);
+ if(($page->{pgpgin}>=$crit_in)||($page->{pgpgout}>=$crit_out)) {
$status = "CRITICAL";
- elsif((($page->{pgpgin}>=$warn_in)&&($page->{pgpgout}>=$warn_out))||($page->{pgmajfault}>=$warn_flt)) {
+ elsif(($page->{pgpgin}>=$warn_in)||($page->{pgpgout}>=$warn_out)) {
$status = "WARNING";

my $perfdata = "|"
."pgpgin=$page->{pgpgin};$warn_in;$crit_in;0 "
."pgpgout=$page->{pgpgout};$warn_out;$crit_out;0 "
- ."pgmajfault=$page->{pgmajfault};$warn_flt;$crit_flt;0 "
."pswpin=$page->{pswpin} pswpout=$page->{pswpout}";

- print "Paging $status : in:$page->{pgpgin},out:$page->{pgpgout},flt:$page->{pgmajfault} $perfdata";
+ print "Paging $status : in:$page->{pgpgin},out:$page->{pgpgout} $perfdata";
else {
print "No data";
@@ -627,7 +626,7 @@
Cpu usage : perl -C -w 90 -c 95 -s 5
Disk usage : perl -D -w 95 -c 100 -u % -p /tmp,/usr,/var
Load average : perl -L -w 10,8,5 -c 20,18,15
- Paging statistics : perl -W -w 10,1000,1 -c 20,2000,20 -s 3
+ Paging statistics : perl -W -w 10,1000 -c 20,2000 -s 3
Process statistics : perl -P -w 100 -c 200
I/O statistics on disk device : perl -I -w 10 -c 5 -p sda1,sda4,sda5,sda6
Network usage : perl -N -w 10000 -c 100000000 -p eth0
Owner's reply

thanks for your comment,
Ussue fixed on v1.5

This plugin is indeed superb.
I found a bug that when using unit=MB for disk usage, the perf data writtens only KB.

So to fix, i made changes on line no. 378 from

$perfdata .= " $mountpoint=$usage$o_unit";


$perfdata .= " $mountpoint=$tmpusage$o_unit;;;0;$tmptotal";

Addition $tmptotal in perf data will set the max MB in the graph.

Let me know,

Owner's reply

thanks for your comment,
Ussue fixed on v1.5

byledistordu, April 25, 2015
I have a perfcounter problem with 1.4.1 :

/usr/lib/nagios/plugins/ -p sda2,sda5 -I -w 100,70 -c 150,100 [16:04:44]
DISK IO OK |sda2_read=0.00;100;150 sda2_write=0.00;70;100|sda5_read=0.00;100;150 sda5_write=0.00;70;100

Need this result :

DISK IO OK |sda2_read=0.00;100;150 sda2_write=0.00;70;100 sda5_read=0.00;100;150 sda5_write=0.00;70;100
Owner's reply

thanks for your comment,
Ussue fixed on v1.5

byBox293, February 4, 2015
0 of 1 people found this review helpful
I recently tried to email the owner of this plugin however I got the following error:

Google tried to deliver your message, but it was rejected by the server for the recipient domain by [].

The error that the other server returned was:
550 5.2.1 This mailbox has been blocked due to inactivity
bymartinboer, January 5, 2015
I ran into 2 really minor issues;
- Sys:Statistics relies on YAML:Syck, but the plugin doesn't complain if that fails.
- the plugin itself does not mention that the -I option needs 2 -w and -c variables.

and I have a small request as well; on virtual machines using lvm you often have a lot of 'disks' attached but most of them are loopback and virtual devices, if you add an option no-fake-disks-for-me-no-sirree (or a shortcut for that), you could loop through the devices in /sys/block/ and use readlink to remove the virtual devices from the list. This saves a lot of output when you don't want to use -p.
byedrendar, November 21, 2014

First of all, I want to congratulate you on your excellent work with this plugin!
I have a question, I don't understand at all how are obtained the net statistics...
If I check TxBytes in /proc/net/dev to review statistics for bond0, I watch a large number in bytes: 7342573046357

Inter-| Receive | Transmit
face |bytes packets errs drop fifo frame compressed multicast|bytes packets errs drop fifo colls carrier compressed
bond0:1259548428146 14687025821 0 0 0 0 0 0 7342573046357 15194696711 0 0 0 0 0 0

But, If I check the Nagios web interface, this amount doesn't match with the previous value:
/proc/net/dev = 7342573046357
Nagios Web = 5323572.80B

How the plugin estimate these values on the Nagios web interface?

Thanks in advance.
byfeisar, September 29, 2014

Thanks for the great plugin. If NFS mounts on the system are unresponsive then an unrelated disk check using this plugin times out.

Can this be fixed?
Hi Experts,

I have issue with this scripts for memory use in percent. I did not checked about other matter but memory usages showing in very less, but other commands for memroy showing accurate value. as below output.

[root@eam1 libexec]# ./ -M -w 99,50 -c 100,50
MEMORY OK : Mem used: 47.27%, Swap used: 3.18% |MemUsed=47.27%;99;100 SwapUsed=3.18%;50;50 MemCached=52.11% SwapCached=0.98% Active=71.91%
[root@eam1 libexec]# sar -r 1 3
Linux 2.6.18-8.el5 ( 09/23/2014

12:15:11 PM kbmemfree kbmemused %memused kbbuffers kbcached kbswpfree kbswpused %swpused kbswpcad
12:15:12 PM 109176 18371676 99.41 550200 9630152 15866008 520284 3.18 160076
12:15:13 PM 118524 18362328 99.36 550200 9630156 15866008 520284 3.18 160076
12:15:14 PM 118648 18362204 99.36 550200 9630156 15866008 520284 3.18 160076
Average: 115449 18365403 99.38 550200 9630155 15866008 520284 3.18 160076
[root@eam1 libexec]# free -m
total used free shared buffers cached
Mem: 18047 17931 116 0 537 9404
-/+ buffers/cache: 7989 10057
Swap: 16002 508 15494

perl script showing 47.27% but sar and nmon and top is showing 98 or 99 percent usage.

Kindly help me for this to get accurate output.

Subhash (
Owner's reply

It's not an issue, but the plugin gets the cache out of the used memory and shows the *real* physical memory usage.

47% MemUsed + 52% MemCached = 99%


bykrizb, June 25, 2014
2 of 2 people found this review helpful
nice plugins. I found one problem:
Example for checking disk suggest using limits for "disk full":
perl -D -w 95 -c 100 -u % -p /tmp,/usr,/var
but plugins uses limits for "disk free":
[krizb@kriznb linux]$ df -h /var
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg0-varF 4.9G 3.2G 1.5G 69% /var
[krizb@kriznb linux]$ /usr/lib64/nagios/plugins/ -D -w 95 -c 100 -u % -p /var
DISK CRITICAL used : /var 30.47% free | /var=3322124KB
[krizb@kriznb linux]$ /usr/lib64/nagios/plugins/ -D -w 5 -c 0 -u % -p /var
DISK OK used : /var 30.47% free | /var=3322124KB
[krizb@kriznb linux]$

Came across your useful plugin for monitoring Linux Stats. I have downloaded the check_linux perl package and installed it on my remote server. But I’ve issues to run the following plugin. To be honest I’m a newbie into this nagios monitoring server and how to configure it. Appreciate if you could lead me to the correct direction

As far as my concerned my steps is as below

At host/remote server

1. root@server# cd /root/nagios
2. root@server nagios# wget
3. root@server nagios# tar –zxvf Sys-Statistics-Linux-0.66.tar.gz
4. root@server nagios# cd Sys-Statistics-Linux-0.66
5. root@server Sys-Statistics-Linux-0.66# perl Makefile.PL
6. root@server Sys-Statistics-Linux-0.66# make
7. root@server Sys-Statistics-Linux-0.66# make install
8. root@server# vi /usr/local/nagios/etc/nrpe.cfg

and I add the harcoded command argument in the nrpe.cfg

# Check network usage on eth0
command[check_net]=/usr/local/nagios/libexec/ -N -w 1000000 -c 1500000 -p eth0 -s 5

9. restart xinetd service && restart nrpe service

At monitoring server

1. Install theLinux Stats plugin same as above

2. go to cd /usr/local/nagios/etc/service.cfg and add the following:

define service{
use generic-service
service_description Network Usage
check_command check_nrpe!check_net
3. go to cd /usr/local/nagios/etc/objects/command.cfg and add the following:

# 'check_net_usage' command definition
define command{
command_name check_net
command_line $USER1$/check_net -I $HOSTADDRESS$ $ARG1$

I believe I miss a few steps and due to this I’m unable to generate the report at Nagios monitoring System. If I go to /usr/local/nagios/libexec/ there is no linux stats plugin available at that directory

Your guidance and advice is highly appreciated
I know some people have asked in earlier comments how to generate perf data to go into nagiosgraph, but I can't get it to work.

Nagiosgraph is saying "no data available". Can you tell me how to get this working?
Page 1 of 3