=head1 SYNOPSIS
-B<rrdtool> B<fetch> I<filename> I<CF>
-S<[B<--resolution>|B<-r> I<resolution>]>
-S<[B<--start>|B<-s> I<start>]>
-S<[B<--end>|B<-e> I<end>]>
+B<rrdtool> B<fetch> I<filename> I<CF>
+S<[B<--resolution>|B<-r> I<resolution>]>
+S<[B<--start>|B<-s> I<start>]>
+S<[B<--end>|B<-e> I<end>]>
=head1 DESCRIPTION
=over 8
-=item I<filename>
+=item I<filename>
the name of the B<RRD> you want to fetch the data from.
-=item I<CF>
+=item I<CF>
the consolidation function that is applied to the data you
want to fetch (AVERAGE,MIN,MAX,LAST)
=head2 RESOLUTION INTERVAL
-In order to get RRDtool to fetch anything other than the finest resolution RRA
-B<both> the start and end time must be specified on boundaries that are
+In order to get RRDtool to fetch anything other than the finest resolution RRA
+B<both> the start and end time must be specified on boundaries that are
multiples of the desired resolution. Consider the following example:
rrdtool create subdata.rrd -s 10 DS:ds0:GAUGE:300:0:U \
=back
-So, if time now is called "t", do
+So, if time now is called "t", do
end time == int(t/900)*900,
- start time == end time - 1hour,
+ start time == end time - 1hour,
resolution == 900.
Using the bash shell, this could look be:
TIME=$(date +%s)
RRDRES=900
rrdtool fetch subdata.rrd AVERAGE -r $RRDRES \
- -e $(echo $(($TIME/$RRDRES*$RRDRES))) -s e-1h
+ -e $(($TIME/$RRDRES*$RRDRES)) -s e-1h
Or in Perl:
=head1 AUTHOR
-Tobias Oetiker <oetiker@ee.ethz.ch>
+Tobias Oetiker <tobi@oetiker.ch>