[Nagios-users] Nagios Graph converting figures to binary bytes rather than decimal

[James Osbourn]

I have Nagios servers installed with standard installation of nagiosgraph. I am seeing some weird behaviour of the graphs showing the data returned from check_disk.

I have a filesystem which has usage as follows:
Filesystem Size Used Avail Use% Mounted on
filer02.uk.xensource.com:/vol/groups/images
450G 310G 141G 69% /usr/groups/images

check_disk returns the following information from the following command
check_disk -w 90 -c 95 -p /usr/groups/images --units=GB

DISK OK - free space: /usr/groups/images 144182 MB (31% inode=99%);| /usr/groups/images=316617MB;460710;460705;0;460800

However, nagiosgraph is showing the following information
Size = 331.79, should be 310
Warning = 477.82, should be 445.5
Critical = 483.18, should be 450
Min = 0, which is correct
Max = 483.18, should be 450



Looking at the GB value and converting to bytes and then back to GB using decimal bytes gives these figures.

Is there any way to make nagiosgraph using binary bytes rather than decimal. I am not that familiar with nagiosgraph or RRD and cannot work out how to make the change.

Many Thanks

James

[Claudio Kuenzler]

Hi James,

Post by James Osbourn
Looking at the GB value and converting to bytes and then back to GB using
decimal bytes gives these figures.
Is there any way to make nagiosgraph using binary bytes rather than
decimal. I am not that familiar with nagiosgraph or RRD and cannot work
out how to make the change.

You will have to manually add an entry into the 'map' file to tell
nagiosgraph to use different values.

My system (df -h) shows:
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg0-root 20G 5.4G 14G 29% /

Nagiosgraph shows:
total: 20.32G
used: 5.45G

You can use the following map entry:

# Service Type: check_disk
# Nagiosgraph regex by Claudio Kuenzler
# Check: /usr/lib/nagios/plugins/check_disk -w 20% -c 10% -p /
# Output: DISK OK - free space: / 235120 MB (66% inode=95%):
# Perfdata: /=119211MB;298635;335964;0;373294
/perfdata:(.*)=(\d+)MB;(\d+);(\d+);(\d+);(\d+).*/
#/perfdata:(\W)=(\d+)MB;(\d+);(\d+);(\d+);(\d+).*/ # only / partition
and push @s, [diskusage,
['used', GAUGE, $2*1000**2 ],
['total', GAUGE, $6*1000**2 ] ];

[James Osbourn]

Hi Claudio,

Thanks for the feedback. Just to make sure, where abouts in the map file should these lines go?

Thanks

James

From: Claudio Kuenzler [mailto:***@claudiokuenzler.com]
Sent: 15 December 2012 15:59
To: Nagios Users List
Subject: Re: [Nagios-users] Nagios Graph converting figures to binary bytes rather than decimal

Hi James,

Looking at the GB value and converting to bytes and then back to GB using decimal bytes gives these figures.

Is there any way to make nagiosgraph using binary bytes rather than decimal. I am not that familiar with nagiosgraph or RRD and cannot work out how to make the change.

You will have to manually add an entry into the 'map' file to tell nagiosgraph to use different values.

My system (df -h) shows:
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg0-root 20G 5.4G 14G 29% /

Nagiosgraph shows:
total: 20.32G
used: 5.45G

You can use the following map entry:

# Service Type: check_disk
# Nagiosgraph regex by Claudio Kuenzler
# Check: /usr/lib/nagios/plugins/check_disk -w 20% -c 10% -p /
# Output: DISK OK - free space: / 235120 MB (66% inode=95%):
# Perfdata: /=119211MB;298635;335964;0;373294
/perfdata:(.*)=(\d+)MB;(\d+);(\d+);(\d+);(\d+).*/
#/perfdata:(\W)=(\d+)MB;(\d+);(\d+);(\d+);(\d+).*/ # only / partition
and push @s, [diskusage,
['used', GAUGE, $2*1000**2 ],
['total', GAUGE, $6*1000**2 ] ];

[Claudio Kuenzler]

Hi Claudio,****
** **
Thanks for the feedback. Just to make sure, where abouts in the map file
should these lines go?****
** **
Thanks****
** **
James

Just make sure you add these lines BEFORE the following part:

##############################################################################################
# default rule. if none of the other rules did anything, then check for
# perfdata that meets the standard format.

[James Osbourn]

Hi Claudio,

I have entered the map entry below based on your example and I am still seeing the results on the graph show as a decimal version of the Bytes value.

/perfdata:(.*)=(\d+)MB;(\d+);(\d+);(\d+);(\d+)/
and push @s, [$1,
['data', GAUGE, $2*1024*1024 ],
['warn', GAUGE, $3*1024*1024 ],
['crit', GAUGE, $4*1024*1024 ],
['min', GAUGE, $5*1024*1024 ],
['max', GAUGE, $6*1024*1024 ] ];

[cid:***@01CDDC69.3ED5FAE0]

Is there something after the map has been processed that takes that value and produces the graphs where the calculation is going wrong?

This is a really annoying issue that I would like to resolve if I can.

Cheers

James

From: James Osbourn
Sent: 15 December 2012 16:16
To: Nagios Users List
Subject: RE: [Nagios-users] Nagios Graph converting figures to binary bytes rather than decimal

Hi Claudio,

Thanks for the feedback. Just to make sure, where abouts in the map file should these lines go?

Thanks

James

From: Claudio Kuenzler [mailto:***@claudiokuenzler.com]
Sent: 15 December 2012 15:59
To: Nagios Users List
Subject: Re: [Nagios-users] Nagios Graph converting figures to binary bytes rather than decimal

Hi James,

Looking at the GB value and converting to bytes and then back to GB using decimal bytes gives these figures.

Is there any way to make nagiosgraph using binary bytes rather than decimal. I am not that familiar with nagiosgraph or RRD and cannot work out how to make the change.

You will have to manually add an entry into the 'map' file to tell nagiosgraph to use different values.

My system (df -h) shows:
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg0-root 20G 5.4G 14G 29% /

Nagiosgraph shows:
total: 20.32G
used: 5.45G

You can use the following map entry:

# Service Type: check_disk
# Nagiosgraph regex by Claudio Kuenzler
# Check: /usr/lib/nagios/plugins/check_disk -w 20% -c 10% -p /
# Output: DISK OK - free space: / 235120 MB (66% inode=95%):
# Perfdata: /=119211MB;298635;335964;0;373294
/perfdata:(.*)=(\d+)MB;(\d+);(\d+);(\d+);(\d+).*/
#/perfdata:(\W)=(\d+)MB;(\d+);(\d+);(\d+);(\d+).*/ # only / partition
and push @s, [diskusage,
['used', GAUGE, $2*1000**2 ],
['total', GAUGE, $6*1000**2 ] ];

[Claudio Kuenzler]

Hi Claudio,****
** **
I have entered the map entry below based on your example and I am still
seeing the results on the graph show as a decimal version of the Bytes
value.****
** **
/perfdata:(.*)=(\d+)MB;(\d+);(\d+);(\d+);(\d+)/****
['data', GAUGE, $2*1024*1024 ],****
['warn', GAUGE, $3*1024*1024 ],****
['crit', GAUGE, $4*1024*1024 ],****
['min', GAUGE, $5*1024*1024 ],****
['max', GAUGE, $6*1024*1024 ] ];

You didn't follow my example, as you're again multiplying with 1024.

Take _another_ look at my example:

['used', GAUGE, $2*1000**2 ],
['total', GAUGE, $6*1000**2 ] ];

[James Osbourn]

Hi Claudio,

I modified your code as it was not working for me and wanted to check what was going on. I have reverted back to using the example that you have given and I am still getting the same result as can be seen here
[cid:***@01CDDD26.57B72AD0]
The filesystem is only 450GB in size, yet the graph values are still showing 460.80, which is the byte value show in decimal GB.

I cannot work out why the graph is showing the wrong values when all other information is correct.

James

From: Claudio Kuenzler [mailto:***@claudiokuenzler.com]
Sent: 18 December 2012 12:15
To: Nagios Users List
Subject: Re: [Nagios-users] Nagios Graph converting figures to binary bytes rather than decimal


Hi Claudio,

I have entered the map entry below based on your example and I am still seeing the results on the graph show as a decimal version of the Bytes value.

/perfdata:(.*)=(\d+)MB;(\d+);(\d+);(\d+);(\d+)/
and push @s, [$1,
['data', GAUGE, $2*1024*1024 ],
['warn', GAUGE, $3*1024*1024 ],
['crit', GAUGE, $4*1024*1024 ],
['min', GAUGE, $5*1024*1024 ],
['max', GAUGE, $6*1024*1024 ] ];

You didn't follow my example, as you're again multiplying with 1024.

Take _another_ look at my example:

['used', GAUGE, $2*1000**2 ],
['total', GAUGE, $6*1000**2 ] ];

[Claudio Kuenzler]

James and I continued the troubleshooting off-list and we came to the
solution, which we want to share of course.
Here's more or less my mail:

---------------------------------------

You're absolutely right, the graphs were not correct. With both *1000**2
and *1024**2.

Actually, thanks to your e-mail I figured that in the past years I've lived
in denial. I must have come up with the multiplication of 1000 in the map
file as a kind of workaround, because the graph was closer to the actual
reality. Then I must have forgotten that and went on....

I broke it down to this:

# df

Filesystem Size Used Avail Use%
Mounted on
/dev/md4 682587992 117456312 530731228 19% /

# df -h

Filesystem Size Used Avail Use% Mounted on
/dev/md4 651G 113G 507G 19% /

So df shows a value in KB (682587992).

The Nagios plugin itself takes this value and presents it in MB (666589):

/=114709MB;533271;599930;0;666589

So in order to present Nagiosgraph the values, we have to go down to the
lowest level, which in this case is Byte.
To get Byte value from the Nagios output we have to multiply it with
1024^2: 666589*1024*1024 = 698969227264

The job of Nagiosgraph is now to take this 698969227264 value and divide it
so often through 1024 until a "reasonable" and human readable value is
given, which would be the 651 GB.

But here's the problem: Nagiosgraph divides 698969227264 through 1000
instead of 1024, showing the graph at 698 GB.
But why? It took me some guesses which I had to confirm but: Nagiosgraph BY
DEFAULT divides through 1000. Probably because the initial reason for rrd
graphs was the graphing of network connections which are usually in bits.
Anyhow we need to tell Nagiosgraph to divide through 1024 for our disk
checks.
There's a special file for that called *rrdopts.conf*. I added the
following lines to it:

# disk values need to be divided by 1024 not 1000
Diskspace /=-b 1024
Root Partition=-b 1024

The string left defines the service description in Nagios. So in my case
this is "Diskspace /". -b 1024 tells Nagiosgraph to take 1024 as a base
value.
See the following entry from the "rrdgraph" manpage:

[*-b*|*--base* *value*] If you are graphing memory (and NOT network
traffic) this switch should be set to 1024 so that one Kb is 1024 byte. For
traffic measurement, 1 kb/s is 1000 b/s.

Now you just have to make sure, that rrdopts.conf is not commented in your
nagiosgraph.conf file and there you go.
Positive thing is that there is no need to recreate the rrd files. This rrd
option is only for viewing/drawing the graphs. Which means that the correct
values are shown immediately.

Hi Claudio,****
** **
I modified your code as it was not working for me and wanted to check what
was going on. I have reverted back to using the example that you have
given and I am still getting the same result as can be seen here****
****
The filesystem is only 450GB in size, yet the graph values are still
showing 460.80, which is the byte value show in decimal GB.****
** **
I cannot work out why the graph is showing the wrong values when all other
information is correct.****
** **
James****
** **
*Sent:* 18 December 2012 12:15
*To:* Nagios Users List
*Subject:* Re: [Nagios-users] Nagios Graph converting figures to binary
bytes rather than decimal****
** **
** **
Hi Claudio,****
****
I have entered the map entry below based on your example and I am still
seeing the results on the graph show as a decimal version of the Bytes
value.****
****
/perfdata:(.*)=(\d+)MB;(\d+);(\d+);(\d+);(\d+)/****
['data', GAUGE, $2*1024*1024 ],****
['warn', GAUGE, $3*1024*1024 ],****
['crit', GAUGE, $4*1024*1024 ],****
['min', GAUGE, $5*1024*1024 ],****
['max', GAUGE, $6*1024*1024 ] ];****
You didn't follow my example, as you're again multiplying with 1024.
['used', GAUGE, $2*1000**2 ],
['total', GAUGE, $6*1000**2 ] ];****
------------------------------------------------------------------------------
LogMeIn Rescue: Anywhere, Anytime Remote support for IT. Free Trial
Remotely access PCs and mobile devices and provide instant support
Improve your efficiency, and focus on delivering more value-add services
Discover what IT Professionals Know. Rescue delivers
http://p.sf.net/sfu/logmein_12329d2d
_______________________________________________
Nagios-users mailing list
https://lists.sourceforge.net/lists/listinfo/nagios-users
::: Please include Nagios version, plugin version (-v) and OS when
reporting any issue.
::: Messages without supporting info will risk being sent to /dev/null

[James Osbourn]

Thanks to Claudio for finding the solution to this issue. To add to the instructions below I found that on my installation the line in nagiosgraph.conf to enable the rrdopts.conf file was commented out. You will need to uncomment this and make sure that it points to the correct place in order for the graphs to be correctly updated.

James

From: Claudio Kuenzler [mailto:***@claudiokuenzler.com]
Sent: 19 December 2012 14:19
To: Nagios Users List
Subject: Re: [Nagios-users] Nagios Graph converting figures to binary bytes rather than decimal

James and I continued the troubleshooting off-list and we came to the solution, which we want to share of course.
Here's more or less my mail:

---------------------------------------

You're absolutely right, the graphs were not correct. With both *1000**2 and *1024**2.

Actually, thanks to your e-mail I figured that in the past years I've lived in denial. I must have come up with the multiplication of 1000 in the map file as a kind of workaround, because the graph was closer to the actual reality. Then I must have forgotten that and went on....

I broke it down to this:

# df

Filesystem Size Used Avail Use% Mounted on
/dev/md4 682587992 117456312 530731228 19% /

# df -h

Filesystem Size Used Avail Use% Mounted on
/dev/md4 651G 113G 507G 19% /

So df shows a value in KB (682587992).

The Nagios plugin itself takes this value and presents it in MB (666589):

/=114709MB;533271;599930;0;666589

So in order to present Nagiosgraph the values, we have to go down to the lowest level, which in this case is Byte.
To get Byte value from the Nagios output we have to multiply it with 1024^2: 666589*1024*1024 = 698969227264

The job of Nagiosgraph is now to take this 698969227264 value and divide it so often through 1024 until a "reasonable" and human readable value is given, which would be the 651 GB.

But here's the problem: Nagiosgraph divides 698969227264 through 1000 instead of 1024, showing the graph at 698 GB.
But why? It took me some guesses which I had to confirm but: Nagiosgraph BY DEFAULT divides through 1000. Probably because the initial reason for rrd graphs was the graphing of network connections which are usually in bits. Anyhow we need to tell Nagiosgraph to divide through 1024 for our disk checks.
There's a special file for that called rrdopts.conf. I added the following lines to it:

# disk values need to be divided by 1024 not 1000
Diskspace /=-b 1024
Root Partition=-b 1024

The string left defines the service description in Nagios. So in my case this is "Diskspace /". -b 1024 tells Nagiosgraph to take 1024 as a base value.
See the following entry from the "rrdgraph" manpage:

[-b|--base value] If you are graphing memory (and NOT network traffic) this switch should be set to 1024 so that one Kb is 1024 byte. For traffic measurement, 1 kb/s is 1000 b/s.

Now you just have to make sure, that rrdopts.conf is not commented in your nagiosgraph.conf file and there you go.
Positive thing is that there is no need to recreate the rrd files. This rrd option is only for viewing/drawing the graphs. Which means that the correct values are shown immediately.


On Tue, Dec 18, 2012 at 2:51 PM, James Osbourn <***@citrix.com<mailto:***@citrix.com>> wrote:
Hi Claudio,

I modified your code as it was not working for me and wanted to check what was going on. I have reverted back to using the example that you have given and I am still getting the same result as can be seen here
The filesystem is only 450GB in size, yet the graph values are still showing 460.80, which is the byte value show in decimal GB.

I cannot work out why the graph is showing the wrong values when all other information is correct.

James

From: Claudio Kuenzler [mailto:***@claudiokuenzler.com<mailto:***@claudiokuenzler.com>]
Sent: 18 December 2012 12:15

To: Nagios Users List
Subject: Re: [Nagios-users] Nagios Graph converting figures to binary bytes rather than decimal


Hi Claudio,

I have entered the map entry below based on your example and I am still seeing the results on the graph show as a decimal version of the Bytes value.

/perfdata:(.*)=(\d+)MB;(\d+);(\d+);(\d+);(\d+)/
and push @s, [$1,
['data', GAUGE, $2*1024*1024 ],
['warn', GAUGE, $3*1024*1024 ],
['crit', GAUGE, $4*1024*1024 ],
['min', GAUGE, $5*1024*1024 ],
['max', GAUGE, $6*1024*1024 ] ];

You didn't follow my example, as you're again multiplying with 1024.

Take _another_ look at my example:

['used', GAUGE, $2*1000**2 ],
['total', GAUGE, $6*1000**2 ] ];

------------------------------------------------------------------------------
LogMeIn Rescue: Anywhere, Anytime Remote support for IT. Free Trial
Remotely access PCs and mobile devices and provide instant support
Improve your efficiency, and focus on delivering more value-add services
Discover what IT Professionals Know. Rescue delivers
http://p.sf.net/sfu/logmein_12329d2d
_______________________________________________
Nagios-users mailing list
Nagios-***@lists.sourceforge.net<mailto:Nagios-***@lists.sourceforge.net>
https://lists.sourceforge.net/lists/listinfo/nagios-users
::: Please include Nagios version, plugin version (-v) and OS when reporting any issue.
::: Messages without supporting info will risk being sent to /dev/null