[wplug] RRDTool

[Bill Moran]

In response to scoob8000 <scoob8000 at gmail.com>:

> Does anyone on the list use and more importaintly understand RRDTool?
> 
> I'm just making some simple bandwidth graphs showing thruput on a single
> interface.
> 
> I have it working, but one option I'm confused on is how many rows to create
> the database with.
> 
> Most examples I see show 500-1000 (enough for a few days of data).  To
> create a monthly or yearly
> graph like MRTG am I not going to have to increase that to 105,120 rows?
> (Data entered every five minutes)

Personally, I would recommend something like mrtg.  mrtg actually uses
RRDTool, but hides the obscurity of it from you.

I've used RRDTool directly, but I won't claim that I truly grok it.  The
thing to remember is that rrds are designed to keep data for long periods
of time, but at lower levels of detail the older the data is.  mrtg manifests
this pretty clearly in the way that it keeps daily/weekly/monthly/yearly
graphs, but those graphs use 5 minute average for daily, 30 minute average
for weekly, etc.  It's actually rrdtool that's doing that.  If you want to
keep a years worth of entries at 5 minute averages, you will need to keep
5 minutes * 1 year (not real math) number of rows, but if you want to allow
the rrd to average out the data as it gets older, you'll only need 1 day's
worth of 5 minute averages, but you'll want 1 week of 30 minute averages,
etc.

HTH

-- 
Bill Moran
http://www.potentialtech.com