[rrd-users] can not update rrd

[Niels Kalle]

Hi everyone.
I'm new to this but I have read the Documentation on rrdtool and some
Tutorials on the Internet before posting to this List, I also have
searched the List for similar posts...
I'm quite stuck on this.

The following is just an example, I have build more complex setups
before and wondered why they failed so I tried, at last, with this small
setup.:

Creation:
rrdtool create test.rrd --start 1171208203 DS:speed:COUNTER:600:0:U
RRA:AVERAGE:0.5:1:12 RRA:AVERAGE:0.5:6:48

The Script which polls data from ifconfig through a cron-job.:
RRD_BIN=/usr/bin/rrdtool
RRD=/home/bla/rrdtool/work/test/test.rrd
faselbla=`ifconfig eth0 | grep RX\ bytes | cut -d ":" -f2 | cut -d " " -f1`
bla=`echo $faselbla | gawk '{print $1}'`
#echo $bla
$RRD_BIN update $RRD N:$bla
exit 0;

which gives me:
suse test # sh -x test-rrd-update.sh
+ RRD_BIN=/usr/bin/rrdtool
+ RRD=/home/nkalle/rrdtool/work/test/test.rrd
++ ifconfig eth0
++ grep 'RX bytes'
++ cut -d : -f2
++ cut -d ' ' -f1
+ faselbla=3503225603
++ echo 3503225603
++ gawk '{print $1}'
+ bla=3503225603
+ echo 3503225603
3503225603
+ /usr/bin/rrdtool update /home/bla/rrdtool/work/test/test.rrd N:3503225603
+ exit 0

(have also tried with an substitution of `date +%s` instead of N before)

no errors, looks good...
but:

suse test # rrdtool fetch test.rrd AVERAGE
                          speed

1171132200: nan
1171134000: nan
1171135800: nan
1171137600: nan
1171139400: nan
1171141200: nan
1171143000: nan
1171144800: nan
1171146600: nan
1171148400: nan
1171150200: nan
1171152000: nan
1171153800: nan
1171155600: nan
1171157400: nan
1171159200: nan
1171161000: nan
1171162800: nan
1171164600: nan
1171166400: nan
1171168200: nan
1171170000: nan
1171171800: nan
1171173600: nan
1171175400: nan
1171177200: nan
1171179000: nan
1171180800: nan
[...]

The same is happening with all my setups.
I really don't get it could someone please explain my error to me?

Best Regards

Niels