[rrd-users] New to RRD

[Russell Handorf]

Greetings all,

I've been reading the documentation and some things dont make sense to 
me. Specifically the purpose of the RRA directive. I think this is where 
my current problem lies with what I am trying to accomplish.

Every night I have a counter of certain activities emailed to me; I'm 
trying to now have this graphed automagically, and by using RRDTool. I'm 
trying to, presently, store two values in a RRD database. Here is how I 
am initializing the DB with two values "sql" and "warns".
rrdtool create /tmp/test.rrd --start <date in the past> --step 300 
DS:sql:ABSOLUTE:300:0:U DS:warns:ABSOLUTE:300:0:U RRA:MAX:0.5:1:105120

 From my understanding, the 300 is when it expects the next value; 
technically this should be 86400 but whenever I try to graph against 
this value I get segfaults.

Anyways, I proceed to store the two values into test.rrd in a loop. The 
values "sql" and "warn" and integers.
rrdtool update /tmp/test.rrd <time in the past of collected data>:$sql:$warn

I then try to graph "sql" by executing
rrdtool graph /tmp/test.gif --start end-1y --end 00:00 
DEF:sql=/tmp/test.rrd:sql:MAX AREA:sql#333333:sql

There's nothing in the graph at all. I then have tried dumping the 
values from the RRD file, only to see that there was nothing in them. 
The *only* way I have been able to get any success is with storing only 
*one* value in the RRD, but even then when I graph and dump the RRD I 
see that the values stored are totally incorrect as to what was entered 
when 'rrdtool update' was executed:
rrdtool create /tmp/test.rrd --start <date in the past> --step 300 
DS:sql:ABSOLUTE:86400:0:10000000 RRA:MAX:0.5:1:6000
$rrdtool update /tmp/test.rrd <time in the past of collected data>:$sql
rrdtool graph /tmp/test.gif --start end-1y --end 00:00 
DEF:sql=/tmp/test.rrd:sql:MAX AREA:sql#333333:sql


What my end goal is that I wish to only store a couple of values per 
day, and then churn out the resulting graph with correct data. So, to 
the folks who have been using this tool for a long time, what am I doing 
incorrectly?

Thanks!