Difference between revisions of "Nagios XI:FAQs"

From Nagios Support Wiki

(Common Problems - Try These Solutions First)
Line 22: Line 22:
Although we plan to support the new version of RHEL 6 in the near future, we currently do not offer support for it.
Although we plan to support the new version of RHEL 6 in the near future, we currently do not offer support for it.
==== Capabilities ====
==== Capabilities ====

Revision as of 10:46, 11 November 2010

Back To Nagios XI Overview

Answers to Frequently Asked Questions (FAQs) regarding Nagios XI can be found here.


What Are FAQs? Frequently Asked Questions, or "FAQs", are answers to questions that are frequently asked in some context.

Common Problems - Try These Solutions First

Follow these steps if you are encountering problems with Nagios XI. These actions solve many commonly asked questions.

  • Clear your browser's cache to get the newest XI javascript code.
    Instructions on how to do it.
  • How To Reset Security Credentials (if performance graphs aren't displayed)
    Select the Reset Security Credentials option in the Admin section and click Update.
  • How To Reset File Permissions (if configuration changes are not taking effect)
    Instructions how.
  • Debugging Configuration Change Problems (if configuration changes are not taking effect)
    Write configuration file tool.

Supported Distributions

Nagios XI is currently supported with the following Linux distributions for both 32 and 64 bit installations:

  • CentOS 5 (Recommended)
  • RHEL 5

Although we plan to support the new version of RHEL 6 in the near future, we currently do not offer support for it.


Is Nagios XI capable of Distributed Monitoring?

Yes it is! There are multiple options for Distributed Monitoring with Nagios.

Nagios Fusion *New*

Nagios Core (the underlying monitoring engine) can be configured for distributed monitoring. For more information, read the Nagios Core documentation on distributed monitoring.

Distributed Monitoring with DNX

System Configuration Problems

Problems Using Nagios XI With Proxies

We do not officially support Nagios XI when you install and use proxy software that restricts traffic to or from the Nagios XI server. There are several reasons for this. First, Nagios XI requires external access for package installation and updates. Package installation and updates may not work when proxies are used. Additionally, the Nagios XI code makes several internal HTTP calls to the local Nagios XI server to import configuration data, apply configuration changes, process AJAX requests, etc. These functions may not work properly when you deploy a proxy, which would result in a non-functional Nagios XI installation.

There are two things that need to be configured to make XI installation work with a proxy; the yum and wget configurations. Do both of these before starting anything about the installation process.

In /etc/yum.conf :

 proxy=http://someproxyserver:port/ # Shouldn't need to be quoted, remember the trailing slash
 proxy_username=myname  # The username you authenticate to your proxy with, if applicable
 proxy_password=mypass  # The password you provide to your proxy, if applicable

In /etc/wgetrc :

 http_proxy=http://myname:mypass@someproxyserver:port/ # All in one string this time
 no_proxy=localhost,,,, # Hosts to exclude from proxying

Quoting is not needed (or helpful) in any of these, but if you have special characters in passwords (especially : or @) and are having problems you probably need to escape them with backslashes.

Installation and Upgrade Problems

SourceGuardian Errors

After upgrading to 2009R1.2C, some users started getting an error about SourceGuardian. Add this line to your /etc/php.ini file:


Once you make that change, restart Apache:

 service restart httpd
Resolving "NSP: Sorry Dave, I can't let you do that" Errors

Session protection was added to 2009R1.2C to prevent CSRF attacks. This code to do this caused some users to see this error. The problem was due to the user's browser caching older versions of the XI javascript code. In order to clear the cache and prevent this from happening, you need to clear your browser's cache. This is typically done (in Firefox) by holding down the shift key and clicking reload. See Other well documented procedures on clearing the browser cache.

"HTTP 500 Error"/"PHP Parse error - Unexpected $end"

For those doing manual installations, some of the tools embedded in Nagios XI use the PHP short tags feature, which is not necessarily enabled on all web servers by default. To fix this issue, locate your php.ini file (located at /etc/php.ini for CentOS installations), and verify that "short_open_tag" is set to "on." We intend to use full tags for future version, but some components and addons may still use them, so we recommend leaving this setting to "on."

Configuration Problems

Modifying The Contents Of /usr/local/nagios/etc
  • You can keep custom configuration files in the /usr/local/nagios/etc/static directory
  • Don't modify config files directly in /usr/local/nagios/etc, as they will be overwritten by the Core Config Manager
Unable To Delete Hosts

Hosts can only be deleted after all of their dependent services and associated relationships have been deleted. Make sure to delete any associated services or other objects before deleting the host.

Host Still Visible After Deletion: (Ghost Hosts)

If you have successfully deleted a host and all of it's services from the Core Config Manager, but you're still seeing it in the status tables, then you most likely have multiple instances of Nagios running on your machine. To make sure all instances are stopped, type the following in the command-line.

 killall nagios
 service nagios start
Network status map parent/child relationship not updating(v1.3)

Underneath the Parents box in the CCM, make sure the "standard" radio button is selected. If "null" is selected your parent host selection doesn't get written to disk. We're working on a method of fixing the CCM so this doesn't happen with several fields.

Core Config Manager Problems
GUI Issues

Most of these are related to IE's implementation of JavaScript. If possible, use a browser that more closely implements the ECMAScript Language Specification.

Configuration Changes

If you make changes to your configuration and they are not reflected in XI, it may be due to file permissions. Here are two options to try:

Performance Graph Problems

Performance Graphs Are Missing Or Not Displayed

This can happen for a variety of reasons, but there are several simple solutions that resolve this issue for most people:

  • Reset Security Credentials
    Select the Reset Security Credentials option in the Admin menu and click Update
  • Reset File Permissions
    Instructions on how to reset file permissions.
  • Further reading
    Forum Article.
  • Make sure your password for Nagios XI only contains alpha-numeric characters. Some users have reported graphs disappearing from using special characters, creating a permissions issue.

Notification Problems

Nagios Admin Account Notifications Not Controlled Through XI
  • The nagiosadmin user was set to use the generic_template contact template, which resulted in notifications not being controlled through the XI interface.
    This can be corrected by changing the user's contact template to be xi_generic_template is the Core Config Manager. This bug was corrected in 2009R1.2 and only effects systems that had/have previous versions installed.
Email Notifications Are Not Going Out

This can happen for a variety of reasons:

  • The nagiosadmin is set to use the generic_template contact template.
    This should be xi_generic_template, and can be modified by using the Core Config Manager. This bug was corrected in 2009R1.2 and only effects systems that had/have previous versions installed.
  • Outbound SMTP connections may be blocked by your border firewall
  • Unauthenticated SMTP relaying may be denied somewhere downstream - try switching email methods from Sendmail to SMTP in the admin section

XI Display Problems

Tables Displaying A Count, But No Results

A recent issue has been identified where characters outside of the ASCII table are being generated by some of the check plugins, which causes an issue with XI's XML generation. The result is a table with a returned count of services, but no actual table data. This issue can be verified by checking the following url:


If this XML page returns an error, it should identify the line number of the issue which can be found in the page source. Below is a code patch that will be included in the next update of XI. Paste this code as a replacement to the xmlentities() function on line 30 of the /usr/local/nagiosxi/html/includes/

 function xmlentities($string){
       $data=str_replace ( array ( '&', '"', "'", '<', '>' ), 
        array ( '&' , '"', ''' , '<' , '>' ), $string );
       preg_match_all('/([\x09\x0a\x0d\x20-\x7e]'. // ASCII characters
       '|[\xc2-\xdf][\x80-\xbf]'. // 2-byte (except overly longs)
       '|\xe0[\xa0-\xbf][\x80-\xbf]'. // 3 byte (except overly longs)
       '|[\xe1-\xec\xee\xef][\x80-\xbf]{2}'. // 3 byte (except overly longs)
       '|\xed[\x80-\x9f][\x80-\xbf])+/', // 3 byte (except UTF-16 surrogates)
       $data, $clean_pieces );
       $clean_output = join('?', $clean_pieces[0] );
       return $clean_output;

Other Issues

Login Screen Keeps Redirecting To Itself

The web browser keeps redirecting to the login screen even after entering login credentials. This has been noticed in Internet Explorer.

Nagios XI uses cookies to save session state. These cookies are set to expire after 30 minutes. If the time on the Nagios XI server is incorrect, the cookies returned to the client's browser might appear to be expired due to the time difference between the client's computer and the Nagios XI server. Solution: Fix the time on the Nagios XI server to ensure it is correct.

Check Services Being Orphaned

Some users have encountered large numbers of warning messages that accumulate quickly that read as follows:

Warning: The check of service <Your Service> on host <Your Host> looks like it was orphaned (results never came back). I'm scheduling an immediate check of the service..

This is most likely caused by multiple instances of Nagios running. To fix this kill all instances of Nagios and then restart the process.

 killall -9 nagios

Then restart Nagios from the Admin menu of the web interface.

Related forum post can be read here.

// ?>