[rrd-users] Malloc error when creating graph (Debian on NSLU2/ARM)

[u7l11ey at mail.lrz-muenchen.de]

Hi all,

I get a strange error when creating a graph. My system is a Linksys NSLU2
running Debian (Linux slug 2.6.18-5-ixp4xx #1 Sun Dec 23 05:17:39 UTC 2007
armv5tel GNU/Linux), I'm using rrdtool 1.2.15. The same problem has also
been reported for 1.2.23, see ticket #111 on the rrdtool website.

This is the graph definition:

rrdtool graph temperatur4.png \
--end now --start end-48799 -a PNG -t "Temperaturverlauf 4h" \
--vertical-label "Temperatur °C" \
--width 800 --height 400 \
DEF:aussen=temperatur.rrd:AF:AVERAGE \
CDEF:aus=aussen,10,/ \
LINE1:aus#ff0000:"Aussen"

Running it produces "ERROR: malloc im->gdes[gdi].data". Notice the
parameter "--start end-48799": The error happens for any values of the
subtractor below 48800! Any values equal or above 48800 will produce the
graph as desired. It also works if the "CDEF" or the size definition is
omitted, but that is not what I want.

I am confused since a graph containing a larger time span shoud use more
resources and therefore be more likely to fail. But in this case, it fails
if the graph contains a shorter time span.

Is anybody running rrdtool on their NSLU2 and also having similar problems
and/or a solution? I'll be happy to supply a complete test case if it
helps.

Regards, Richard