[mrtg] Re: Pre-generate graphs with MRTG/RRD setup

[Pavel Ruzicka]

Hello,

> I am running MRTG with RRD integration as described at
> http://people.ee.ethz.ch/~oetiker/webtools/mrtg/mrtg-rrd.html because I
> need to graph values higher than what MRTG can handle. I have about 200
> targets and I have an indexing script that calls 14all to generate the
> graphs for subsets of the targets. These pages can contain up to 100 graphs
> from various targets. With MRTG only, this was very fast because MRTG would
> create the graphs every five minutes. Now that I have RRD integrated, the
> graphs are generated by the 14all script instead, which is very slow.
>
> Is there any way to get MRTG/RRD to automatically generate the graphs every
> five minutes like MRTG does on its own? Is there a recommended method?

I have MRTG with RRDTool and about 7000 targets. I have my own indexmaker, 
which generates HTML pages with targets, one page per device. On html pages
I have links to 14all.cgi script which generates pages with 4 graphs for one 
target.
I have simple CGI script which can search "string" in html pages.

Generating of graphs is very fast. In past I was problems with speed of 
generating graphs.

There are few critical things:
----------------------------------
It's important to use modPERL in Apache.

There are performance problem, when kernel updates rrdfiles from cache
to disk.

You need enough of RAM for running MRTG and caching of all rrd files.
On linux you can look for free ram with "top" command. It's better, when swap
is not much used. Newer kernels (2.6) have better memory management.

Other thing is speed of harddrive. One 10000rpm SCSI Ultra320 harddrive
is enough ;-)

Processor speed is not critical. 500MHz to 1GHz is enough.

With more targets you can tune filesystem. For example you can enable
for ext2 and ext3 filesystem directory caching.

--
Unsubscribe mailto:mrtg-request at list.ee.ethz.ch?subject=unsubscribe
Archive     http://www.ee.ethz.ch/~slist/mrtg
FAQ         http://faq.mrtg.org    Homepage     http://www.mrtg.org
WebAdmin    http://www.ee.ethz.ch/~slist/lsg2.cgi