[mrtg] Chunky rrdtool graph

[Max (MRTG list)]

Hi all,

trying to make my mrtg graphs have the same scale while they are using a 
log Y axis it was recommended that I try rrdtool.

I'm not sure if this list also covers them, or if I have to subscribe to 
another list, but I am having a (as far as I can tell weird) problem 
with my graph.

If I make the graph the default size (-w 400) I get a rather nice 
resolution graph, and i'm happy with its look, but...

I want to have a longer graph, I want to have (-w 1200 -s -72h) rather 
than the default of (-w 400 -s -24h).

Now the weird part, the scale looks correct for the expanded size, but 
the graph is a lot more chunky looking :(

Confusing the heck out of me.

if I do 24 hrs (-w 400 -s 24h) I have my base graph...
if I do 48 hrs (-w 800 -s 48h) I have a longer graph looking ok
but...
if I do 72 hrs (-w 1200 -s 72h) The scale looks the same, but the data 
lines look a lot more chuncky.

It is the same data, the only part changed is the -w (width) and -s 
(start) options.

I have listed my command line below...

(sorry for listing all three even though there is only the graph name 
and the last line changed. I didn't want to make you thik I had changed 
other variables somewhere...


rrdtool graph /var/www/rrdtool/24h.png  \
   DEF:inoctets=/var/www/rrdtool/XH9949.rrd:input:AVERAGE        \
   DEF:outoctets=/var/www/rrdtool/XH9949.rrd:output:AVERAGE      \
   VDEF:MaxIn=inoctets,MAXIMUM                                   \
   VDEF:AvgIn=inoctets,AVERAGE                                   \
   VDEF:CurrentIn=inoctets,LAST                                  \
   VDEF:MaxOut=outoctets,MAXIMUM                                 \
   VDEF:AvgOut=outoctets,AVERAGE                                 \
   VDEF:CurrentOut=outoctets,LAST                                \
   COMMENT:"\t\tMax\t\t\t   Average\t\t\tCurrent\n" \
   AREA:inoctets#00FF00:"In"                                     \
   GPRINT:MaxIn:"%8.2lf %sbps"                                   \
   GPRINT:AvgIn:"\t%8.2lf %sbps"                                 \
   GPRINT:CurrentIn:"\t%8.2lf %sbps\n"                           \
   LINE1:outoctets#0000FF:"Out"                                  \
   GPRINT:MaxOut:"%7.2lf %sbps"                                  \
   GPRINT:AvgOut:"\t%8.2lf %sbps"                                \
   GPRINT:CurrentOut:"\t%8.2lf %sbps\n"                          \
   --title "Traffic for adsl modem"                              \
   -l $MinBytes -u $MaxBytes  -r --units=si --logarithmic        \
   -s -24h -w 400


rrdtool graph /var/www/rrdtool/48h.png  \
   DEF:inoctets=/var/www/rrdtool/XH9949.rrd:input:AVERAGE        \
   DEF:outoctets=/var/www/rrdtool/XH9949.rrd:output:AVERAGE      \
   VDEF:MaxIn=inoctets,MAXIMUM                                   \
   VDEF:AvgIn=inoctets,AVERAGE                                   \
   VDEF:CurrentIn=inoctets,LAST                                  \
   VDEF:MaxOut=outoctets,MAXIMUM                                 \
   VDEF:AvgOut=outoctets,AVERAGE                                 \
   VDEF:CurrentOut=outoctets,LAST                                \
   COMMENT:"\t\tMax\t\t\t   Average\t\t\tCurrent\n" \
   AREA:inoctets#00FF00:"In"                                     \
   GPRINT:MaxIn:"%8.2lf %sbps"                                   \
   GPRINT:AvgIn:"\t%8.2lf %sbps"                                 \
   GPRINT:CurrentIn:"\t%8.2lf %sbps\n"                           \
   LINE1:outoctets#0000FF:"Out"                                  \
   GPRINT:MaxOut:"%7.2lf %sbps"                                  \
   GPRINT:AvgOut:"\t%8.2lf %sbps"                                \
   GPRINT:CurrentOut:"\t%8.2lf %sbps\n"                          \
   --title "Traffic for adsl modem"                              \
   -l $MinBytes -u $MaxBytes  -r --units=si --logarithmic        \
   -s -48h -w 800

rrdtool graph /var/www/rrdtool/72h.png  \
   DEF:inoctets=/var/www/rrdtool/XH9949.rrd:input:AVERAGE        \
   DEF:outoctets=/var/www/rrdtool/XH9949.rrd:output:AVERAGE      \
   VDEF:MaxIn=inoctets,MAXIMUM                                   \
   VDEF:AvgIn=inoctets,AVERAGE                                   \
   VDEF:CurrentIn=inoctets,LAST                                  \
   VDEF:MaxOut=outoctets,MAXIMUM                                 \
   VDEF:AvgOut=outoctets,AVERAGE                                 \
   VDEF:CurrentOut=outoctets,LAST                                \
   COMMENT:"\t\tMax\t\t\t   Average\t\t\tCurrent\n" \
   AREA:inoctets#00FF00:"In"                                     \
   GPRINT:MaxIn:"%8.2lf %sbps"                                   \
   GPRINT:AvgIn:"\t%8.2lf %sbps"                                 \
   GPRINT:CurrentIn:"\t%8.2lf %sbps\n"                           \
   LINE1:outoctets#0000FF:"Out"                                  \
   GPRINT:MaxOut:"%7.2lf %sbps"                                  \
   GPRINT:AvgOut:"\t%8.2lf %sbps"                                \
   GPRINT:CurrentOut:"\t%8.2lf %sbps\n"                          \
   --title "Traffic for adsl modem"                              \
   -l $MinBytes -u $MaxBytes  -r --units=si --logarithmic        \
   -s -72h -w 1200




I can't work out why the last graph looks chunky.

Not sure if you can post .png files to the list, so assuming you can't, 
I have posted the three graphs at
http://www.corporateturtles.com/rrdtool/

this is a static page I made for this email, those graphs are not being 
updated.


The ONLY possible idea i have is that the last graph is complaining as 
it is going further than the data available (just recently started 
logging with rrdtool), but i'm not sure why that would affect the 
plotting of the parts where the data exists.

Any ideas?


Max
Dunedin
New Zealand.