From f3e6c9663369d011b241c6fb2c8fd5312f98cacf Mon Sep 17 00:00:00 2001

From: Jan ONDREJ <ondrejj@salstar.sk>

Date: Thu, 7 Oct 2010 17:28:48 +0400

Subject: [PATCH 6/6] Prevent check_swap from returning OK, if no swap activated

My swap was not activated on boot for unknown reason and nagios does not

report this as a problem. Here is an example:

[root@kecom ~]# rpm -q nagios-plugins

nagios-plugins-1.4.13-11.fc10.i386

[root@kecom ~]# /usr/lib/nagios/plugins/check_swap -w 80% -c 40% -c 1 -w 2

SWAP CRITICAL - 100% free (0 MB out of 0 MB) |swap=0MB;0;0;0;0

If there is no swap and users is trying to test percentage of free swap,

consider 0 MB free swap space as problem, or of free/total raises division

by zero, then set percentage to 0%, not to 100%.

Steps to Reproduce:

1. make sure, your swap is empty or it's usage is not large

2. swapoff -a

3. /usr/lib/nagios/plugins/check_swap -w 80% -c 40%

Actual results:

SWAP OK - 100% free (0 MB out of 0 MB) |swap=0MB;0;0;0;0

Expected results:

SWAP CRITICAL - 0% free (0 MB out of 0 MB) |swap=0MB;0;0;0;0

Additional info:

https://bugzilla.redhat.com/512559

---

 plugins/check_swap.c |    2 +-

 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/plugins/check_swap.c b/plugins/check_swap.c

index ce1f602..6d1d0c1 100644

--- a/plugins/check_swap.c

+++ b/plugins/check_swap.c

@@ -124,7 +124,7 @@ main (int argc, char **argv)

 			free_swap_mb += dskfree_mb;

 			if (allswaps) {

 				if (dsktotal_mb == 0)

-					percent=100.0;

+					percent = 0.0;

 				else

 					percent = 100 * (((double) dskused_mb) / ((double) dsktotal_mb));

 				result = max_state (result, check_swap (percent, dskfree_mb));

-- 

1.7.2.3