[rrd-users] Re: rrd graph not matching figures

Dave Lugo dlugo at etherboy.com
Sat Nov 6 17:32:35 MET 2004

On Sat, 6 Nov 2004, Peter Schuller wrote:
> Short version: It seems rrdtool is graphing the DEF:s rather than the CDEF:s. 
> How can I make it graph the CDEF:s? I want to apply a modifier (in this case 
> dividie by 125) to graph bandwidth in kilobits rather than bytes.
> Long version:
> I've set up rrdtool+snmpd on a couple of hosts now and on both hosts I have 
> experienced the same issue. For example, on one host I generate the graph as 
> follows (minus some linebreaks added here):
> /usr/local/bin/rrdtool graph /usr/local/rrd/www/bw-xl0-60-1h.png -a PNG \
>   -h 100  -w 800 -s -3600 -S 60 -v "Data throughput" \    
>     "DEF:in=/usr/local/rrd/bw-xl0-60.rrd:in:AVERAGE" \                                                                         
>     "DEF:out=/usr/local/rrd/bw-xl0-60.rrd:out:AVERAGE" \                                                                       
>     'CDEF:kbin=in,125,/' \                                                                                                     
>     'CDEF:kbout=out,125,/' \                                                                                                   
>     'AREA:in#00FF00:Bandwidth In'                        


>     LINE1:out#0000FF:Bandwidth Out\j' \                           


>     'GPRINT:kbin:LAST:Last Bandwidth In\:  %3.2lf KBps'\         
>     'GPRINT:kbout:LAST:Last Bandwidth Out\:   %3.2lf KBps\j' \     
>     'GPRINT:kbin:AVERAGE:Average Bandwidth In\: %3.2lf KBps' \
>     'GPRINT:kbout:AVERAGE:Average Bandwidth Out\:%3.2lf KBps\j' 2>\
>     &1 1>/dev/null
> The value of the CDEF:s are definitely correct because the numbers printed at 
> the bottom by the GRPINT:s are correct. But the graph itself seems to show 
> the raw values from the RRD. For example, to test the graph I sustained an 
> outgoing transfer rate of about 9.4 mBYTEs/second (according to wget). Now, 
> the value of the CDEF ("last bandwidth out") in the resulting graph agrees 
> with wget and 'nload xl0', but the graph says "10M" which looks suspiciously 
> like the number of octets transfered per second (i.e., about ten million).
> How can I tell rrdgraph to graph the CDEF:s rather than the DEF:s, if that's 
> the proper terminology?
> Thanks!

Dave Lugo   dlugo at etherboy.com    LC Unit #260   TINLC
Have you hugged your firewall today?   No spam, thanks.
Are you the police?  . . . .  No ma'am, we're sysadmins.

Unsubscribe mailto:rrd-users-request at list.ee.ethz.ch?subject=unsubscribe
Help        mailto:rrd-users-request at list.ee.ethz.ch?subject=help
Archive     http://www.ee.ethz.ch/~slist/rrd-users
WebAdmin    http://www.ee.ethz.ch/~slist/lsg2.cgi

More information about the rrd-users mailing list