Useful Links:

Introducing...

NagVis is a visualization addon for the well known network managment system Nagios.

NagVis can be used to visualize Nagios Data, e.g. to display IT processes like a mail system or a network infrastructure.

FAQ

What is NDO?

Question: The installation instructions mention "NDO" and recommend to use this as a base for the NagVis NDO Backend. I've never heared about that. What is NDO?

Answer: NDO (Nagios Data Out) is an official addon for Nagios 2.x developed by Ethan Galstad. It brings database support back to Nagios. You can get it at Sourceforge. You can get some documentation on Nagios.org. NDO is not developed by the NagVis Project. Please report issues regarding NDO directy to the Nagios-devel mailinglist.

How to run NagVis WITHOUT authentication?

We do not recommend such a setup but here are two possible ways to do it:

mod_rewrite

The following mod_rewrite config maps the user "nagiosadmin" to NagVis:

  RewriteEngine   on
  RewriteLock     var/log/rewrite.lck
  RewriteLog      /dev/null
  RewriteLogLevel 0

  # The following line is the really important step,
  # it tells the webserver that the user "nagiosadmin" has
  # successfully authenticated and is sending the request,
  # regardless who is sending it really.

  RewriteRule     /nagvis/ - [E=REMOTE_USER:nagiosadmin]

.htaccess

A second way to "disable" the authentication is setting the variable REMOTE_USER via .htaccess file. Place a file called .htaccess with the following content in the NagVis root directory:

SetEnv REMOTE_USER nagiosusername

Acknowledgements are not recognized in NagVis

Question: A service or a host is displayed as critical even if it is acknowledged. I think the _sack.png or _ack.png should be displayed instead.

Answer: The recognition of acknowledgements is only supported by the NDO Backend. The HTML Backend does not support this and will not support this in the future.

The background image is not displayed

Question: The background image is not visible, only a placeholder (e.g. a red x or a white background) is displayed by the browser

Answer: It is likely that your PHP memory limit is too low. Increase"memory_limit" in your php.ini file e.g. memory_limit = 24M

Can I add an external URL to the map rotations?

Question: I have another webpage which shows some interesting information. Can I add this page to the map rotations?

Answer: Yes, you can. You can add the URL to the comma separated map list (''maps'' parameter). The URL has to be enclosed by [ and ]. In this mode NagVis tries to read the contents of that URL and parses the HTML code on the NagVis page. So NagVis needs access to the webpage.

The NagVis Automap does not load

Question: When I open the new automap of NagVis 1.3 the request results in a blank page or some curious error message. What can I do?

Answer: At the first step you should take a look at the last lines of your web server's error log. On my system this is ''/var/log/apache2/error_log''. If there is something like

Fatal error: Allowed memory size of  bytes exhausted at ...

This is the result of a memory limit set too low. You have to increase the memory_limit in your php configuration (For details see php.ini documentation).

The NagVis Automap shows only imageNotExists

Question: When I open the Automap of NagVis it only displays the error message "imageNotExists". The web server's error_log shows a message like this: "Error: Layout was not done. Missing layout plugins?". What to do?

Answer: There are some plugins of Graphviz missing. Maybe the needed plugins (e.g. for png rendering) are not installed. In some packages these plugins just are not configured. To configure the plugins you can simply execute "# dot -c".

The WUI shows no context menu in Firefox

Question: My firefox does only show the browser's context menu in NagVis WUI. The WUI context-menu is only shown in background.

Answer: There is an option in the firefox configuration called "dom.event.contextmenu.enabled". When this is set to false no page can override the browsers context menu. If you'd like to use the WUI for configuration you should set this option to true to be able to use the menu.

The date/time is shown wrong in NagVis

See the FAQ below.

Problem with timezone settings

Question: The hover menu is not displayed. An alert message is shown:
Error in ajax request handler:
Error: (2048) date() [function.date]: It is not safe to rely on the system's timezone settings. Please use the date.timezone setting, the TZ environment variable or the date_default_timezone_set() function. In case you used any of those methods and you are still getting this warning, you most likely misspelled the timezone identifier. We selected 'Europe/Berlin' for 'CEST/2.0/DST' instead

Answer: The PHP date and time functions have been rewritten in PHP 5.1. Since these rewrite you have to set the timezone in your system. This could be done in PHP code, in php.ini (date.timezone) or the cleanest way: system wide through the TZ environment variable. Get this working, restart your webserver and the error will be gone.

Only a white page is displayed when calling NagVis in the browser

Question: There is only a white page in the browser when I call an URL of NagVis.

Answer: There seems to be a problem with some PHP proceeding. At first you should take a look at your webserver's error log.

Maybe you see a message like "memory limit exceeded". That's because of the NagVis pages need more memory while building than PHP can allocate. To fix this you can try to increase the memory of your PHP installation. This can be done by editing the value of memory_limit in your php.ini.

Some translations do not work in NagVis 1.4!

Question: Some translations do not work in NagVis 1.4. For example english language works but the german language is not being translated.

Answer: The problem is that the php gettext module needs the language directory in /usr/lib/locale. When you install the language packages of your distribution which creates that directories it will work. In Ubuntu for example you have to install the language-support-d package to get the german translation to work.

Where can I find nice images for the shapes on my maps?

Question: I'd like to draw some shapes on my maps but I don't have any license for drawing tools like Microsoft Visio. Where can I get free shapes for visualizing my IT infrastructure?

Answer: Here are some pages which contain nice images: