Nagios Support Forum

Here's the questions-
For all support requests, we need to know:
Linux Distribution and version?
CentOS 6.4 x86_64
VMware Image or Manual Install of XI?
VMWare Image

No special configurations, running Nagios XI 2014R1.2.

Right now on all our managed routers, the bandwidth on the router interfaces all report back as zero. When I run the check manually I also get usage as zero (it's not). I am attempting to troubleshoot this using the command "LANG=C LC_ALL=C /usr/bin/mrtg /etc/mrtg/mrtg.cfg –check"
, and I am running into a lot of error messages, with three main categories of errors:

2014-07-08 15:19:42: ERROR: Target[xxxx][_IN_] ' $target->[4662]{$mode} ' did not eval into defined data
2014-07-08 15:19:42: ERROR: Cannot update /var/lib/mrtg/xxxxxx.rrd with '1404846637:U:U' /var/lib/mrtg/xxxxxx.rrd: illegal attempt to update using time 1404846637 when last update time is 1404847172 (minimum one second step)
2014-07-08 15:19:42: ERROR: Cannot update /var/lib/mrtg/xxxxx.rrd with '1404846636:U:U' could not lock RRD

I am thinking about just deleting all existing RRD data and starting over, is that supported, and if so how would I do that?

Thanks in advance

Yes, you could delete them, it looks like your time may be off? Is it?:
Are your bandwidth checks the only ones experiencing rrd/perfdata related issues? Depending on how many of those eval errors you are seeing mrtg may be timing out before it reaches some of your 'true' hosts. You will want to remove all old configurations you are no longer using as mrtg will run through the file from top to bottom regardless. See:

http://assets.nagios.com/downloads/nagi ... Router.pdf