[rrd-users] can't update rrd with data.

[A Darren Dunham]

On Mon, Nov 23, 2009 at 12:38:15PM -0800, John Stile wrote:
> At the end of my backup script, if the rrd does not exist, it is created
> via the following:
> 
>   rrdtool \
>     create \
>     "${RRD_File}" \
>     --step 86400 \
>     "DS:size:GAUGE:87000:U:U" \
>     "RRA:LAST:0.5:1:365" \
>     "RRA:LAST:0.5:30:60"

> After this step, I try to add the size of the backup with the following
> command:
>   rrdtool update "${RRD_File}" "N:${size}"

Are you only running this once?

> The script log shows that the two variables ${RRD_File} and ${size} are
> populated with the correct data.
> 
> I set the heartbeat to 87000 seconds (slightly higher than the step of
> 86400 seconds) to allow extra time for the backup to complete.
> 
> After the update, when I do a dump, nothing is stored in either rra.

Although this is of type "GAUGE", RRD internally is still keeping track
of things as rates, so you must have 2 data points (within a heartbeat
distance) before anything can be shown.

Can you show some sample data that you're providing to rrdupdate?

-- 
Darren